{"openapi":"3.1.0","info":{"title":"Halyard Rates","version":"1.0.0","description":"Historical interest-rate data, cleaned and ready to load, for analysts and the agents that work for them. For demonstration only. This transaction runs on a test network with test money, and has no value. Every purchase is a transaction on the test network the buyer names (`network` in the request's body, a CAIP-2 id; without it, `eip155:84532`), paid in its test USDC to this shop's seller account there, and makes its own agreement, whose hash the payment carries. The doors over HTTP: each offer's door, paid by x402 or, where its offers say so, by MPP's `evm` method; and UCP's checkout (UCP 2026-08-25, https://ucp.dev/2026-08-25/services/shopping/rest.openapi.json), paid through the x402 payment handler `com.integraledger.lcp.x402` its profile declares at https://halyard-rates.integraledger.com/.well-known/ucp. MCP is at https://halyard-rates.integraledger.com/mcp. How to buy, in prose: https://halyard-rates.integraledger.com/llms.txt."},"servers":[{"url":"https://halyard-rates.integraledger.com"}],"x-service-info":{"categories":["commerce"],"docs":{"homepage":"https://halyard-rates.integraledger.com/","llms":"https://halyard-rates.integraledger.com/llms.txt","apiReference":"https://halyard-rates.integraledger.com/agents"}},"paths":{"/buy/yield-curve-decade":{"get":{"operationId":"buy_yield_curve_decade","summary":"Buy US Treasury yield curves, 2015 to 2024","description":"Every business day's par yield curve from the US Treasury for ten years, one month to thirty years, as one CSV of 2,501 rows: ISO dates, one column per maturity, and a blank where the Treasury published no rate. $40.00, paid as 0.004 USDC. Paid when bought (x402 `exact`). Paid by x402 or, on an EVM network, by MPP on the network the body's `network` names; a `GET` has no body, and is paid on `eip155:84532`. For demonstration only. This transaction runs on a test network with test money, and has no value.","parameters":[{"name":"PAYMENT-SIGNATURE","in":"header","required":false,"description":"The signed x402 payment, base64, on the request that repeats the one answered 402.","schema":{"type":"string"}}],"x-payment-info":{"offers":[{"intent":"charge","method":"x402","amount":"4000","currency":"0x036CbD53842c5426634e7929541eC2318f3dCF7e","description":"US Treasury yield curves, 2015 to 2024: $40.00, paid as 0.004 USDC. x402 `exact` on Base Sepolia (`eip155:84532`, named `{\"network\": \"eip155:84532\"}` in the body, the default), in USDC (`0x036CbD53842c5426634e7929541eC2318f3dCF7e`), paid to the payee `0x0C6239c982cE5B2db1D58b714259dc7B7455D501`."},{"intent":"charge","method":"evm","amount":"4000","currency":"0x036CbD53842c5426634e7929541eC2318f3dCF7e","description":"US Treasury yield curves, 2015 to 2024: $40.00, paid as 0.004 USDC. MPP `evm` `charge`, credential `authorization` (EIP-3009), on Base Sepolia (chain id 84532, `eip155:84532`, named `{\"network\": \"eip155:84532\"}` in the body, the default), in USDC (`0x036CbD53842c5426634e7929541eC2318f3dCF7e`), paid to the payee `0x0C6239c982cE5B2db1D58b714259dc7B7455D501`."},{"intent":"charge","method":"x402","amount":"4000","currency":"0x3600000000000000000000000000000000000000","description":"US Treasury yield curves, 2015 to 2024: $40.00, paid as 0.004 USDC. x402 `exact` on Arc testnet (`eip155:5042002`, named `{\"network\": \"eip155:5042002\"}` in the body), in USDC (`0x3600000000000000000000000000000000000000`), paid to the payee `0x0C6239c982cE5B2db1D58b714259dc7B7455D501`."},{"intent":"charge","method":"evm","amount":"4000","currency":"0x3600000000000000000000000000000000000000","description":"US Treasury yield curves, 2015 to 2024: $40.00, paid as 0.004 USDC. MPP `evm` `charge`, credential `authorization` (EIP-3009), on Arc testnet (chain id 5042002, `eip155:5042002`, named `{\"network\": \"eip155:5042002\"}` in the body), in USDC (`0x3600000000000000000000000000000000000000`), paid to the payee `0x0C6239c982cE5B2db1D58b714259dc7B7455D501`."},{"intent":"charge","method":"x402","amount":"4000","currency":"0x5425890298aed601595a70AB815c96711a31Bc65","description":"US Treasury yield curves, 2015 to 2024: $40.00, paid as 0.004 USDC. x402 `exact` on Avalanche® Fuji (`eip155:43113`, named `{\"network\": \"eip155:43113\"}` in the body), in USDC (`0x5425890298aed601595a70AB815c96711a31Bc65`), paid to the payee `0x0C6239c982cE5B2db1D58b714259dc7B7455D501`."},{"intent":"charge","method":"evm","amount":"4000","currency":"0x5425890298aed601595a70AB815c96711a31Bc65","description":"US Treasury yield curves, 2015 to 2024: $40.00, paid as 0.004 USDC. MPP `evm` `charge`, credential `authorization` (EIP-3009), on Avalanche® Fuji (chain id 43113, `eip155:43113`, named `{\"network\": \"eip155:43113\"}` in the body), in USDC (`0x5425890298aed601595a70AB815c96711a31Bc65`), paid to the payee `0x0C6239c982cE5B2db1D58b714259dc7B7455D501`."},{"intent":"charge","method":"x402","amount":"4000","currency":"0.0.429274","description":"US Treasury yield curves, 2015 to 2024: $40.00, paid as 0.004 USDC. x402 `exact` on Hedera testnet (`hedera:testnet`, named `{\"network\": \"hedera:testnet\"}` in the body), in USDC (`0.0.429274`), paid to the payee `0.0.11173957`."},{"intent":"charge","method":"x402","amount":"40000","currency":"CBIELTK6YBZJU5UP2WWQEUCYKLPU6AUNZ2BQ4WWFEIE3USCIHMXQDAMA","description":"US Treasury yield curves, 2015 to 2024: $40.00, paid as 0.004 USDC. x402 `exact` on Stellar testnet (`stellar:testnet`, named `{\"network\": \"stellar:testnet\"}` in the body), in USDC (`CBIELTK6YBZJU5UP2WWQEUCYKLPU6AUNZ2BQ4WWFEIE3USCIHMXQDAMA`), paid to the payee `GCDGZBXG3PNUXEZWERCS7WE35QXUUYV4WD2AYAUD5A73QQG76LKRBLDY`."},{"intent":"charge","method":"x402","amount":"4000","currency":"4zMMC9srt5Ri5X14GAgXhaHii3GnPAEERYPJgZJDncDU","description":"US Treasury yield curves, 2015 to 2024: $40.00, paid as 0.004 USDC. x402 `exact` on Solana devnet (`solana:EtWTRABZaYq6iMfeYKouRu166VU2xqa1`, named `{\"network\": \"solana:EtWTRABZaYq6iMfeYKouRu166VU2xqa1\"}` in the body), in USDC (`4zMMC9srt5Ri5X14GAgXhaHii3GnPAEERYPJgZJDncDU`), paid to the payee `7G32bRuk36oneaaZR5UNxUbithWzwqyGANCEm2KPn1D3`."},{"intent":"charge","method":"x402","amount":"4000","currency":"5553444300000000000000000000000000000000","description":"US Treasury yield curves, 2015 to 2024: $40.00, paid as 0.004 USDC. x402 `exact` on XRPL Testnet (`xrpl:1`, named `{\"network\": \"xrpl:1\"}` in the body), in USDC (`5553444300000000000000000000000000000000`), paid to the payee `rP2TcSm1j65dFuDcJjFRvt4U2KXZryjdKi`."},{"intent":"charge","method":"x402","amount":"4000","currency":"10458941","description":"US Treasury yield curves, 2015 to 2024: $40.00, paid as 0.004 USDC. x402 `exact` on Algorand testnet (`algorand:SGO1GKSzyE7IEPItTxCByw9x8FmnrCDe`, named `{\"network\": \"algorand:SGO1GKSzyE7IEPItTxCByw9x8FmnrCDe\"}` in the body), in USDC (`10458941`), paid to the payee `UQ6EUR44FU7ADT22WHVAIQS225PSBWD43PW5K3KKFCY6T6CKXNPKVPD5BA`."},{"intent":"charge","method":"x402","amount":"4000","currency":"0x1c7D4B196Cb0C7B01d743Fbc6116a902379C7238","description":"US Treasury yield curves, 2015 to 2024: $40.00, paid as 0.004 USDC. x402 `exact` on Ethereum Sepolia (`eip155:11155111`, named `{\"network\": \"eip155:11155111\"}` in the body), in USDC (`0x1c7D4B196Cb0C7B01d743Fbc6116a902379C7238`), paid to the payee `0x0C6239c982cE5B2db1D58b714259dc7B7455D501`."},{"intent":"charge","method":"evm","amount":"4000","currency":"0x1c7D4B196Cb0C7B01d743Fbc6116a902379C7238","description":"US Treasury yield curves, 2015 to 2024: $40.00, paid as 0.004 USDC. MPP `evm` `charge`, credential `authorization` (EIP-3009), on Ethereum Sepolia (chain id 11155111, `eip155:11155111`, named `{\"network\": \"eip155:11155111\"}` in the body), in USDC (`0x1c7D4B196Cb0C7B01d743Fbc6116a902379C7238`), paid to the payee `0x0C6239c982cE5B2db1D58b714259dc7B7455D501`."},{"intent":"charge","method":"x402","amount":"4000","currency":"0x75faf114eafb1BDbe2F0316DF893fd58CE46AA4d","description":"US Treasury yield curves, 2015 to 2024: $40.00, paid as 0.004 USDC. x402 `exact` on Arbitrum Sepolia (`eip155:421614`, named `{\"network\": \"eip155:421614\"}` in the body), in USDC (`0x75faf114eafb1BDbe2F0316DF893fd58CE46AA4d`), paid to the payee `0x0C6239c982cE5B2db1D58b714259dc7B7455D501`."},{"intent":"charge","method":"evm","amount":"4000","currency":"0x75faf114eafb1BDbe2F0316DF893fd58CE46AA4d","description":"US Treasury yield curves, 2015 to 2024: $40.00, paid as 0.004 USDC. MPP `evm` `charge`, credential `authorization` (EIP-3009), on Arbitrum Sepolia (chain id 421614, `eip155:421614`, named `{\"network\": \"eip155:421614\"}` in the body), in USDC (`0x75faf114eafb1BDbe2F0316DF893fd58CE46AA4d`), paid to the payee `0x0C6239c982cE5B2db1D58b714259dc7B7455D501`."},{"intent":"charge","method":"x402","amount":"4000","currency":"0x5fd84259d66Cd46123540766Be93DFE6D43130D7","description":"US Treasury yield curves, 2015 to 2024: $40.00, paid as 0.004 USDC. x402 `exact` on OP Sepolia (`eip155:11155420`, named `{\"network\": \"eip155:11155420\"}` in the body), in USDC (`0x5fd84259d66Cd46123540766Be93DFE6D43130D7`), paid to the payee `0x0C6239c982cE5B2db1D58b714259dc7B7455D501`."},{"intent":"charge","method":"evm","amount":"4000","currency":"0x5fd84259d66Cd46123540766Be93DFE6D43130D7","description":"US Treasury yield curves, 2015 to 2024: $40.00, paid as 0.004 USDC. MPP `evm` `charge`, credential `authorization` (EIP-3009), on OP Sepolia (chain id 11155420, `eip155:11155420`, named `{\"network\": \"eip155:11155420\"}` in the body), in USDC (`0x5fd84259d66Cd46123540766Be93DFE6D43130D7`), paid to the payee `0x0C6239c982cE5B2db1D58b714259dc7B7455D501`."},{"intent":"charge","method":"x402","amount":"4000","currency":"0x41E94Eb019C0762f9Bfcf9Fb1E58725BfB0e7582","description":"US Treasury yield curves, 2015 to 2024: $40.00, paid as 0.004 USDC. x402 `exact` on Polygon Amoy (`eip155:80002`, named `{\"network\": \"eip155:80002\"}` in the body), in USDC (`0x41E94Eb019C0762f9Bfcf9Fb1E58725BfB0e7582`), paid to the payee `0x0C6239c982cE5B2db1D58b714259dc7B7455D501`."},{"intent":"charge","method":"evm","amount":"4000","currency":"0x41E94Eb019C0762f9Bfcf9Fb1E58725BfB0e7582","description":"US Treasury yield curves, 2015 to 2024: $40.00, paid as 0.004 USDC. MPP `evm` `charge`, credential `authorization` (EIP-3009), on Polygon Amoy (chain id 80002, `eip155:80002`, named `{\"network\": \"eip155:80002\"}` in the body), in USDC (`0x41E94Eb019C0762f9Bfcf9Fb1E58725BfB0e7582`), paid to the payee `0x0C6239c982cE5B2db1D58b714259dc7B7455D501`."},{"intent":"charge","method":"x402","amount":"4000","currency":"0x31d0220469e10c4E71834a79b1f276d740d3768F","description":"US Treasury yield curves, 2015 to 2024: $40.00, paid as 0.004 USDC. x402 `exact` on Unichain Sepolia (`eip155:1301`, named `{\"network\": \"eip155:1301\"}` in the body), in USDC (`0x31d0220469e10c4E71834a79b1f276d740d3768F`), paid to the payee `0x0C6239c982cE5B2db1D58b714259dc7B7455D501`."},{"intent":"charge","method":"evm","amount":"4000","currency":"0x31d0220469e10c4E71834a79b1f276d740d3768F","description":"US Treasury yield curves, 2015 to 2024: $40.00, paid as 0.004 USDC. MPP `evm` `charge`, credential `authorization` (EIP-3009), on Unichain Sepolia (chain id 1301, `eip155:1301`, named `{\"network\": \"eip155:1301\"}` in the body), in USDC (`0x31d0220469e10c4E71834a79b1f276d740d3768F`), paid to the payee `0x0C6239c982cE5B2db1D58b714259dc7B7455D501`."},{"intent":"charge","method":"x402","amount":"4000","currency":"0x66145f38cBAC35Ca6F1Dfb4914dF98F1614aeA88","description":"US Treasury yield curves, 2015 to 2024: $40.00, paid as 0.004 USDC. x402 `exact` on World Chain Sepolia (`eip155:4801`, named `{\"network\": \"eip155:4801\"}` in the body), in USDC (`0x66145f38cBAC35Ca6F1Dfb4914dF98F1614aeA88`), paid to the payee `0x0C6239c982cE5B2db1D58b714259dc7B7455D501`."},{"intent":"charge","method":"evm","amount":"4000","currency":"0x66145f38cBAC35Ca6F1Dfb4914dF98F1614aeA88","description":"US Treasury yield curves, 2015 to 2024: $40.00, paid as 0.004 USDC. MPP `evm` `charge`, credential `authorization` (EIP-3009), on World Chain Sepolia (chain id 4801, `eip155:4801`, named `{\"network\": \"eip155:4801\"}` in the body), in USDC (`0x66145f38cBAC35Ca6F1Dfb4914dF98F1614aeA88`), paid to the payee `0x0C6239c982cE5B2db1D58b714259dc7B7455D501`."},{"intent":"charge","method":"x402","amount":"4000","currency":"0xFabab97dCE620294D2B0b0e46C68964e326300Ac","description":"US Treasury yield curves, 2015 to 2024: $40.00, paid as 0.004 USDC. x402 `exact` on Ink Sepolia (`eip155:763373`, named `{\"network\": \"eip155:763373\"}` in the body), in USDC (`0xFabab97dCE620294D2B0b0e46C68964e326300Ac`), paid to the payee `0x0C6239c982cE5B2db1D58b714259dc7B7455D501`."},{"intent":"charge","method":"evm","amount":"4000","currency":"0xFabab97dCE620294D2B0b0e46C68964e326300Ac","description":"US Treasury yield curves, 2015 to 2024: $40.00, paid as 0.004 USDC. MPP `evm` `charge`, credential `authorization` (EIP-3009), on Ink Sepolia (chain id 763373, `eip155:763373`, named `{\"network\": \"eip155:763373\"}` in the body), in USDC (`0xFabab97dCE620294D2B0b0e46C68964e326300Ac`), paid to the payee `0x0C6239c982cE5B2db1D58b714259dc7B7455D501`."},{"intent":"charge","method":"x402","amount":"4000","currency":"0x01C5C0122039549AD1493B8220cABEdD739BC44E","description":"US Treasury yield curves, 2015 to 2024: $40.00, paid as 0.004 USDC. x402 `exact` on Celo Sepolia (`eip155:11142220`, named `{\"network\": \"eip155:11142220\"}` in the body), in USDC (`0x01C5C0122039549AD1493B8220cABEdD739BC44E`), paid to the payee `0x0C6239c982cE5B2db1D58b714259dc7B7455D501`."},{"intent":"charge","method":"evm","amount":"4000","currency":"0x01C5C0122039549AD1493B8220cABEdD739BC44E","description":"US Treasury yield curves, 2015 to 2024: $40.00, paid as 0.004 USDC. MPP `evm` `charge`, credential `authorization` (EIP-3009), on Celo Sepolia (chain id 11142220, `eip155:11142220`, named `{\"network\": \"eip155:11142220\"}` in the body), in USDC (`0x01C5C0122039549AD1493B8220cABEdD739BC44E`), paid to the payee `0x0C6239c982cE5B2db1D58b714259dc7B7455D501`."},{"intent":"charge","method":"x402","amount":"4000","currency":"0x534b2f3A21130d7a60830c2Df862319e593943A3","description":"US Treasury yield curves, 2015 to 2024: $40.00, paid as 0.004 USDC. x402 `exact` on Monad testnet (`eip155:10143`, named `{\"network\": \"eip155:10143\"}` in the body), in USDC (`0x534b2f3A21130d7a60830c2Df862319e593943A3`), paid to the payee `0x0C6239c982cE5B2db1D58b714259dc7B7455D501`."},{"intent":"charge","method":"evm","amount":"4000","currency":"0x534b2f3A21130d7a60830c2Df862319e593943A3","description":"US Treasury yield curves, 2015 to 2024: $40.00, paid as 0.004 USDC. MPP `evm` `charge`, credential `authorization` (EIP-3009), on Monad testnet (chain id 10143, `eip155:10143`, named `{\"network\": \"eip155:10143\"}` in the body), in USDC (`0x534b2f3A21130d7a60830c2Df862319e593943A3`), paid to the payee `0x0C6239c982cE5B2db1D58b714259dc7B7455D501`."},{"intent":"charge","method":"x402","amount":"4000","currency":"0x4fCF1784B31630811181f670Aea7A7bEF803eaED","description":"US Treasury yield curves, 2015 to 2024: $40.00, paid as 0.004 USDC. x402 `exact` on Sei testnet (`eip155:1328`, named `{\"network\": \"eip155:1328\"}` in the body), in USDC (`0x4fCF1784B31630811181f670Aea7A7bEF803eaED`), paid to the payee `0x0C6239c982cE5B2db1D58b714259dc7B7455D501`."},{"intent":"charge","method":"evm","amount":"4000","currency":"0x4fCF1784B31630811181f670Aea7A7bEF803eaED","description":"US Treasury yield curves, 2015 to 2024: $40.00, paid as 0.004 USDC. MPP `evm` `charge`, credential `authorization` (EIP-3009), on Sei testnet (chain id 1328, `eip155:1328`, named `{\"network\": \"eip155:1328\"}` in the body), in USDC (`0x4fCF1784B31630811181f670Aea7A7bEF803eaED`), paid to the payee `0x0C6239c982cE5B2db1D58b714259dc7B7455D501`."},{"intent":"charge","method":"x402","amount":"4000","currency":"0x0BA304580ee7c9a980CF72e55f5Ed2E9fd30Bc51","description":"US Treasury yield curves, 2015 to 2024: $40.00, paid as 0.004 USDC. x402 `exact` on Sonic testnet (`eip155:14601`, named `{\"network\": \"eip155:14601\"}` in the body), in USDC (`0x0BA304580ee7c9a980CF72e55f5Ed2E9fd30Bc51`), paid to the payee `0x0C6239c982cE5B2db1D58b714259dc7B7455D501`."},{"intent":"charge","method":"evm","amount":"4000","currency":"0x0BA304580ee7c9a980CF72e55f5Ed2E9fd30Bc51","description":"US Treasury yield curves, 2015 to 2024: $40.00, paid as 0.004 USDC. MPP `evm` `charge`, credential `authorization` (EIP-3009), on Sonic testnet (chain id 14601, `eip155:14601`, named `{\"network\": \"eip155:14601\"}` in the body), in USDC (`0x0BA304580ee7c9a980CF72e55f5Ed2E9fd30Bc51`), paid to the payee `0x0C6239c982cE5B2db1D58b714259dc7B7455D501`."},{"intent":"charge","method":"x402","amount":"4000","currency":"0x7433b41C6c5e1d58D4Da99483609520255ab661B","description":"US Treasury yield curves, 2015 to 2024: $40.00, paid as 0.004 USDC. x402 `exact` on Morph Hoodi (`eip155:2910`, named `{\"network\": \"eip155:2910\"}` in the body), in USDC (`0x7433b41C6c5e1d58D4Da99483609520255ab661B`), paid to the payee `0x0C6239c982cE5B2db1D58b714259dc7B7455D501`."},{"intent":"charge","method":"evm","amount":"4000","currency":"0x7433b41C6c5e1d58D4Da99483609520255ab661B","description":"US Treasury yield curves, 2015 to 2024: $40.00, paid as 0.004 USDC. MPP `evm` `charge`, credential `authorization` (EIP-3009), on Morph Hoodi (chain id 2910, `eip155:2910`, named `{\"network\": \"eip155:2910\"}` in the body), in USDC (`0x7433b41C6c5e1d58D4Da99483609520255ab661B`), paid to the payee `0x0C6239c982cE5B2db1D58b714259dc7B7455D501`."},{"intent":"charge","method":"x402","amount":"4000","currency":"0xEb33dc5fac03833e132593659e1dE7256aB59794","description":"US Treasury yield curves, 2015 to 2024: $40.00, paid as 0.004 USDC. x402 `exact` on Cronos testnet (`eip155:338`, named `{\"network\": \"eip155:338\"}` in the body), in USDC (`0xEb33dc5fac03833e132593659e1dE7256aB59794`), paid to the payee `0x0C6239c982cE5B2db1D58b714259dc7B7455D501`."},{"intent":"charge","method":"evm","amount":"4000","currency":"0xEb33dc5fac03833e132593659e1dE7256aB59794","description":"US Treasury yield curves, 2015 to 2024: $40.00, paid as 0.004 USDC. MPP `evm` `charge`, credential `authorization` (EIP-3009), on Cronos testnet (chain id 338, `eip155:338`, named `{\"network\": \"eip155:338\"}` in the body), in USDC (`0xEb33dc5fac03833e132593659e1dE7256aB59794`), paid to the payee `0x0C6239c982cE5B2db1D58b714259dc7B7455D501`."},{"intent":"charge","method":"x402","amount":"4000","currency":"0xcfC8330f4BCAB529c625D12781b1C19466A9Fc8B","description":"US Treasury yield curves, 2015 to 2024: $40.00, paid as 0.004 USDC. x402 `exact` on Pharos Atlantic (`eip155:688689`, named `{\"network\": \"eip155:688689\"}` in the body), in USDC (`0xcfC8330f4BCAB529c625D12781b1C19466A9Fc8B`), paid to the payee `0x0C6239c982cE5B2db1D58b714259dc7B7455D501`."},{"intent":"charge","method":"evm","amount":"4000","currency":"0xcfC8330f4BCAB529c625D12781b1C19466A9Fc8B","description":"US Treasury yield curves, 2015 to 2024: $40.00, paid as 0.004 USDC. MPP `evm` `charge`, credential `authorization` (EIP-3009), on Pharos Atlantic (chain id 688689, `eip155:688689`, named `{\"network\": \"eip155:688689\"}` in the body), in USDC (`0xcfC8330f4BCAB529c625D12781b1C19466A9Fc8B`), paid to the payee `0x0C6239c982cE5B2db1D58b714259dc7B7455D501`."}]},"responses":{"200":{"description":"Paid and delivered. `PAYMENT-RESPONSE` holds the x402 settlement, base64, or `Payment-Receipt` MPP's receipt, base64url, for a payment made with MPP; the body holds the delivery and the proof's address.","headers":{"PAYMENT-RESPONSE":{"schema":{"type":"string"}},"Payment-Receipt":{"schema":{"type":"string"}}}},"202":{"description":"The payment is sent and not yet confirmed. Send the same request again, or ask the proof's record."},"400":{"description":"Refused: the request lacks what the offer asks for, names a network this shop does not know, or names one this way of paying is never paid on, or is not as this operation says."},"402":{"description":"Payment required. `PAYMENT-REQUIRED` holds the x402 version 2 `PaymentRequired`, base64; the body holds it too. Its `extensions.legalContext.info` holds the agreement's hash H and its link: fetch the link, hash the bytes with SHA-256, and sign only if they match. Send the same request again with `PAYMENT-SIGNATURE`. The same answer carries MPP's challenge, `WWW-Authenticate: Payment … method=\"evm\", intent=\"charge\"`, for the same amount of the same token to the same payee, with an agreement of its own: its `opaque` (base64url JSON) holds `legalContext`, `lcp:sha256:` and that agreement's H, and `legalContextUrl`, its link. Check it the same way, and pay with `Authorization: Payment <credential>`, an `authorization` credential (EIP-3009) as `mppx` signs it. Pay one challenge, not both.","headers":{"PAYMENT-REQUIRED":{"schema":{"type":"string"}},"WWW-Authenticate":{"description":"MPP's `Payment` challenge, method `evm`, intent `charge`.","schema":{"type":"string"}}}},"502":{"description":"Paid, and not delivered: the seller tried again, and gave up. `PAYMENT-RESPONSE` holds the settlement, which succeeded; the body is the purchase."},"503":{"description":"Before a payment: the network named is not offered now, or the agreement could not be issued; nothing was taken. After a payment: paid, and not yet delivered, the seller tries again; `PAYMENT-RESPONSE` holds the settlement, which succeeded, `Retry-After` when to ask again, and the body is the purchase."}}},"post":{"operationId":"buy_yield_curve_decade_post","summary":"Buy US Treasury yield curves, 2015 to 2024","description":"Every business day's par yield curve from the US Treasury for ten years, one month to thirty years, as one CSV of 2,501 rows: ISO dates, one column per maturity, and a blank where the Treasury published no rate. $40.00, paid as 0.004 USDC. Paid when bought (x402 `exact`). Paid by x402 or, on an EVM network, by MPP on the network the body's `network` names. For demonstration only. This transaction runs on a test network with test money, and has no value.","parameters":[{"name":"PAYMENT-SIGNATURE","in":"header","required":false,"description":"The signed x402 payment, base64, on the request that repeats the one answered 402.","schema":{"type":"string"}}],"requestBody":{"required":false,"content":{"application/json":{"schema":{"type":"object","additionalProperties":false,"required":[],"properties":{"network":{"type":"string","enum":["eip155:84532","eip155:5042002","eip155:43113","hedera:testnet","stellar:testnet","solana:EtWTRABZaYq6iMfeYKouRu166VU2xqa1","xrpl:1","algorand:SGO1GKSzyE7IEPItTxCByw9x8FmnrCDe","eip155:11155111","eip155:421614","eip155:11155420","eip155:80002","eip155:1301","eip155:4801","eip155:763373","eip155:11142220","eip155:10143","eip155:1328","eip155:14601","eip155:2910","eip155:338","eip155:688689"],"description":"The network the checkout is paid on, a CAIP-2 id; without it, `eip155:84532`. The paid request repeats it, as it repeats the whole request."}}},"example":{}}}},"x-payment-info":{"offers":[{"intent":"charge","method":"x402","amount":"4000","currency":"0x036CbD53842c5426634e7929541eC2318f3dCF7e","description":"US Treasury yield curves, 2015 to 2024: $40.00, paid as 0.004 USDC. x402 `exact` on Base Sepolia (`eip155:84532`, named `{\"network\": \"eip155:84532\"}` in the body, the default), in USDC (`0x036CbD53842c5426634e7929541eC2318f3dCF7e`), paid to the payee `0x0C6239c982cE5B2db1D58b714259dc7B7455D501`."},{"intent":"charge","method":"evm","amount":"4000","currency":"0x036CbD53842c5426634e7929541eC2318f3dCF7e","description":"US Treasury yield curves, 2015 to 2024: $40.00, paid as 0.004 USDC. MPP `evm` `charge`, credential `authorization` (EIP-3009), on Base Sepolia (chain id 84532, `eip155:84532`, named `{\"network\": \"eip155:84532\"}` in the body, the default), in USDC (`0x036CbD53842c5426634e7929541eC2318f3dCF7e`), paid to the payee `0x0C6239c982cE5B2db1D58b714259dc7B7455D501`."},{"intent":"charge","method":"x402","amount":"4000","currency":"0x3600000000000000000000000000000000000000","description":"US Treasury yield curves, 2015 to 2024: $40.00, paid as 0.004 USDC. x402 `exact` on Arc testnet (`eip155:5042002`, named `{\"network\": \"eip155:5042002\"}` in the body), in USDC (`0x3600000000000000000000000000000000000000`), paid to the payee `0x0C6239c982cE5B2db1D58b714259dc7B7455D501`."},{"intent":"charge","method":"evm","amount":"4000","currency":"0x3600000000000000000000000000000000000000","description":"US Treasury yield curves, 2015 to 2024: $40.00, paid as 0.004 USDC. MPP `evm` `charge`, credential `authorization` (EIP-3009), on Arc testnet (chain id 5042002, `eip155:5042002`, named `{\"network\": \"eip155:5042002\"}` in the body), in USDC (`0x3600000000000000000000000000000000000000`), paid to the payee `0x0C6239c982cE5B2db1D58b714259dc7B7455D501`."},{"intent":"charge","method":"x402","amount":"4000","currency":"0x5425890298aed601595a70AB815c96711a31Bc65","description":"US Treasury yield curves, 2015 to 2024: $40.00, paid as 0.004 USDC. x402 `exact` on Avalanche® Fuji (`eip155:43113`, named `{\"network\": \"eip155:43113\"}` in the body), in USDC (`0x5425890298aed601595a70AB815c96711a31Bc65`), paid to the payee `0x0C6239c982cE5B2db1D58b714259dc7B7455D501`."},{"intent":"charge","method":"evm","amount":"4000","currency":"0x5425890298aed601595a70AB815c96711a31Bc65","description":"US Treasury yield curves, 2015 to 2024: $40.00, paid as 0.004 USDC. MPP `evm` `charge`, credential `authorization` (EIP-3009), on Avalanche® Fuji (chain id 43113, `eip155:43113`, named `{\"network\": \"eip155:43113\"}` in the body), in USDC (`0x5425890298aed601595a70AB815c96711a31Bc65`), paid to the payee `0x0C6239c982cE5B2db1D58b714259dc7B7455D501`."},{"intent":"charge","method":"x402","amount":"4000","currency":"0.0.429274","description":"US Treasury yield curves, 2015 to 2024: $40.00, paid as 0.004 USDC. x402 `exact` on Hedera testnet (`hedera:testnet`, named `{\"network\": \"hedera:testnet\"}` in the body), in USDC (`0.0.429274`), paid to the payee `0.0.11173957`."},{"intent":"charge","method":"x402","amount":"40000","currency":"CBIELTK6YBZJU5UP2WWQEUCYKLPU6AUNZ2BQ4WWFEIE3USCIHMXQDAMA","description":"US Treasury yield curves, 2015 to 2024: $40.00, paid as 0.004 USDC. x402 `exact` on Stellar testnet (`stellar:testnet`, named `{\"network\": \"stellar:testnet\"}` in the body), in USDC (`CBIELTK6YBZJU5UP2WWQEUCYKLPU6AUNZ2BQ4WWFEIE3USCIHMXQDAMA`), paid to the payee `GCDGZBXG3PNUXEZWERCS7WE35QXUUYV4WD2AYAUD5A73QQG76LKRBLDY`."},{"intent":"charge","method":"x402","amount":"4000","currency":"4zMMC9srt5Ri5X14GAgXhaHii3GnPAEERYPJgZJDncDU","description":"US Treasury yield curves, 2015 to 2024: $40.00, paid as 0.004 USDC. x402 `exact` on Solana devnet (`solana:EtWTRABZaYq6iMfeYKouRu166VU2xqa1`, named `{\"network\": \"solana:EtWTRABZaYq6iMfeYKouRu166VU2xqa1\"}` in the body), in USDC (`4zMMC9srt5Ri5X14GAgXhaHii3GnPAEERYPJgZJDncDU`), paid to the payee `7G32bRuk36oneaaZR5UNxUbithWzwqyGANCEm2KPn1D3`."},{"intent":"charge","method":"x402","amount":"4000","currency":"5553444300000000000000000000000000000000","description":"US Treasury yield curves, 2015 to 2024: $40.00, paid as 0.004 USDC. x402 `exact` on XRPL Testnet (`xrpl:1`, named `{\"network\": \"xrpl:1\"}` in the body), in USDC (`5553444300000000000000000000000000000000`), paid to the payee `rP2TcSm1j65dFuDcJjFRvt4U2KXZryjdKi`."},{"intent":"charge","method":"x402","amount":"4000","currency":"10458941","description":"US Treasury yield curves, 2015 to 2024: $40.00, paid as 0.004 USDC. x402 `exact` on Algorand testnet (`algorand:SGO1GKSzyE7IEPItTxCByw9x8FmnrCDe`, named `{\"network\": \"algorand:SGO1GKSzyE7IEPItTxCByw9x8FmnrCDe\"}` in the body), in USDC (`10458941`), paid to the payee `UQ6EUR44FU7ADT22WHVAIQS225PSBWD43PW5K3KKFCY6T6CKXNPKVPD5BA`."},{"intent":"charge","method":"x402","amount":"4000","currency":"0x1c7D4B196Cb0C7B01d743Fbc6116a902379C7238","description":"US Treasury yield curves, 2015 to 2024: $40.00, paid as 0.004 USDC. x402 `exact` on Ethereum Sepolia (`eip155:11155111`, named `{\"network\": \"eip155:11155111\"}` in the body), in USDC (`0x1c7D4B196Cb0C7B01d743Fbc6116a902379C7238`), paid to the payee `0x0C6239c982cE5B2db1D58b714259dc7B7455D501`."},{"intent":"charge","method":"evm","amount":"4000","currency":"0x1c7D4B196Cb0C7B01d743Fbc6116a902379C7238","description":"US Treasury yield curves, 2015 to 2024: $40.00, paid as 0.004 USDC. MPP `evm` `charge`, credential `authorization` (EIP-3009), on Ethereum Sepolia (chain id 11155111, `eip155:11155111`, named `{\"network\": \"eip155:11155111\"}` in the body), in USDC (`0x1c7D4B196Cb0C7B01d743Fbc6116a902379C7238`), paid to the payee `0x0C6239c982cE5B2db1D58b714259dc7B7455D501`."},{"intent":"charge","method":"x402","amount":"4000","currency":"0x75faf114eafb1BDbe2F0316DF893fd58CE46AA4d","description":"US Treasury yield curves, 2015 to 2024: $40.00, paid as 0.004 USDC. x402 `exact` on Arbitrum Sepolia (`eip155:421614`, named `{\"network\": \"eip155:421614\"}` in the body), in USDC (`0x75faf114eafb1BDbe2F0316DF893fd58CE46AA4d`), paid to the payee `0x0C6239c982cE5B2db1D58b714259dc7B7455D501`."},{"intent":"charge","method":"evm","amount":"4000","currency":"0x75faf114eafb1BDbe2F0316DF893fd58CE46AA4d","description":"US Treasury yield curves, 2015 to 2024: $40.00, paid as 0.004 USDC. MPP `evm` `charge`, credential `authorization` (EIP-3009), on Arbitrum Sepolia (chain id 421614, `eip155:421614`, named `{\"network\": \"eip155:421614\"}` in the body), in USDC (`0x75faf114eafb1BDbe2F0316DF893fd58CE46AA4d`), paid to the payee `0x0C6239c982cE5B2db1D58b714259dc7B7455D501`."},{"intent":"charge","method":"x402","amount":"4000","currency":"0x5fd84259d66Cd46123540766Be93DFE6D43130D7","description":"US Treasury yield curves, 2015 to 2024: $40.00, paid as 0.004 USDC. x402 `exact` on OP Sepolia (`eip155:11155420`, named `{\"network\": \"eip155:11155420\"}` in the body), in USDC (`0x5fd84259d66Cd46123540766Be93DFE6D43130D7`), paid to the payee `0x0C6239c982cE5B2db1D58b714259dc7B7455D501`."},{"intent":"charge","method":"evm","amount":"4000","currency":"0x5fd84259d66Cd46123540766Be93DFE6D43130D7","description":"US Treasury yield curves, 2015 to 2024: $40.00, paid as 0.004 USDC. MPP `evm` `charge`, credential `authorization` (EIP-3009), on OP Sepolia (chain id 11155420, `eip155:11155420`, named `{\"network\": \"eip155:11155420\"}` in the body), in USDC (`0x5fd84259d66Cd46123540766Be93DFE6D43130D7`), paid to the payee `0x0C6239c982cE5B2db1D58b714259dc7B7455D501`."},{"intent":"charge","method":"x402","amount":"4000","currency":"0x41E94Eb019C0762f9Bfcf9Fb1E58725BfB0e7582","description":"US Treasury yield curves, 2015 to 2024: $40.00, paid as 0.004 USDC. x402 `exact` on Polygon Amoy (`eip155:80002`, named `{\"network\": \"eip155:80002\"}` in the body), in USDC (`0x41E94Eb019C0762f9Bfcf9Fb1E58725BfB0e7582`), paid to the payee `0x0C6239c982cE5B2db1D58b714259dc7B7455D501`."},{"intent":"charge","method":"evm","amount":"4000","currency":"0x41E94Eb019C0762f9Bfcf9Fb1E58725BfB0e7582","description":"US Treasury yield curves, 2015 to 2024: $40.00, paid as 0.004 USDC. MPP `evm` `charge`, credential `authorization` (EIP-3009), on Polygon Amoy (chain id 80002, `eip155:80002`, named `{\"network\": \"eip155:80002\"}` in the body), in USDC (`0x41E94Eb019C0762f9Bfcf9Fb1E58725BfB0e7582`), paid to the payee `0x0C6239c982cE5B2db1D58b714259dc7B7455D501`."},{"intent":"charge","method":"x402","amount":"4000","currency":"0x31d0220469e10c4E71834a79b1f276d740d3768F","description":"US Treasury yield curves, 2015 to 2024: $40.00, paid as 0.004 USDC. x402 `exact` on Unichain Sepolia (`eip155:1301`, named `{\"network\": \"eip155:1301\"}` in the body), in USDC (`0x31d0220469e10c4E71834a79b1f276d740d3768F`), paid to the payee `0x0C6239c982cE5B2db1D58b714259dc7B7455D501`."},{"intent":"charge","method":"evm","amount":"4000","currency":"0x31d0220469e10c4E71834a79b1f276d740d3768F","description":"US Treasury yield curves, 2015 to 2024: $40.00, paid as 0.004 USDC. MPP `evm` `charge`, credential `authorization` (EIP-3009), on Unichain Sepolia (chain id 1301, `eip155:1301`, named `{\"network\": \"eip155:1301\"}` in the body), in USDC (`0x31d0220469e10c4E71834a79b1f276d740d3768F`), paid to the payee `0x0C6239c982cE5B2db1D58b714259dc7B7455D501`."},{"intent":"charge","method":"x402","amount":"4000","currency":"0x66145f38cBAC35Ca6F1Dfb4914dF98F1614aeA88","description":"US Treasury yield curves, 2015 to 2024: $40.00, paid as 0.004 USDC. x402 `exact` on World Chain Sepolia (`eip155:4801`, named `{\"network\": \"eip155:4801\"}` in the body), in USDC (`0x66145f38cBAC35Ca6F1Dfb4914dF98F1614aeA88`), paid to the payee `0x0C6239c982cE5B2db1D58b714259dc7B7455D501`."},{"intent":"charge","method":"evm","amount":"4000","currency":"0x66145f38cBAC35Ca6F1Dfb4914dF98F1614aeA88","description":"US Treasury yield curves, 2015 to 2024: $40.00, paid as 0.004 USDC. MPP `evm` `charge`, credential `authorization` (EIP-3009), on World Chain Sepolia (chain id 4801, `eip155:4801`, named `{\"network\": \"eip155:4801\"}` in the body), in USDC (`0x66145f38cBAC35Ca6F1Dfb4914dF98F1614aeA88`), paid to the payee `0x0C6239c982cE5B2db1D58b714259dc7B7455D501`."},{"intent":"charge","method":"x402","amount":"4000","currency":"0xFabab97dCE620294D2B0b0e46C68964e326300Ac","description":"US Treasury yield curves, 2015 to 2024: $40.00, paid as 0.004 USDC. x402 `exact` on Ink Sepolia (`eip155:763373`, named `{\"network\": \"eip155:763373\"}` in the body), in USDC (`0xFabab97dCE620294D2B0b0e46C68964e326300Ac`), paid to the payee `0x0C6239c982cE5B2db1D58b714259dc7B7455D501`."},{"intent":"charge","method":"evm","amount":"4000","currency":"0xFabab97dCE620294D2B0b0e46C68964e326300Ac","description":"US Treasury yield curves, 2015 to 2024: $40.00, paid as 0.004 USDC. MPP `evm` `charge`, credential `authorization` (EIP-3009), on Ink Sepolia (chain id 763373, `eip155:763373`, named `{\"network\": \"eip155:763373\"}` in the body), in USDC (`0xFabab97dCE620294D2B0b0e46C68964e326300Ac`), paid to the payee `0x0C6239c982cE5B2db1D58b714259dc7B7455D501`."},{"intent":"charge","method":"x402","amount":"4000","currency":"0x01C5C0122039549AD1493B8220cABEdD739BC44E","description":"US Treasury yield curves, 2015 to 2024: $40.00, paid as 0.004 USDC. x402 `exact` on Celo Sepolia (`eip155:11142220`, named `{\"network\": \"eip155:11142220\"}` in the body), in USDC (`0x01C5C0122039549AD1493B8220cABEdD739BC44E`), paid to the payee `0x0C6239c982cE5B2db1D58b714259dc7B7455D501`."},{"intent":"charge","method":"evm","amount":"4000","currency":"0x01C5C0122039549AD1493B8220cABEdD739BC44E","description":"US Treasury yield curves, 2015 to 2024: $40.00, paid as 0.004 USDC. MPP `evm` `charge`, credential `authorization` (EIP-3009), on Celo Sepolia (chain id 11142220, `eip155:11142220`, named `{\"network\": \"eip155:11142220\"}` in the body), in USDC (`0x01C5C0122039549AD1493B8220cABEdD739BC44E`), paid to the payee `0x0C6239c982cE5B2db1D58b714259dc7B7455D501`."},{"intent":"charge","method":"x402","amount":"4000","currency":"0x534b2f3A21130d7a60830c2Df862319e593943A3","description":"US Treasury yield curves, 2015 to 2024: $40.00, paid as 0.004 USDC. x402 `exact` on Monad testnet (`eip155:10143`, named `{\"network\": \"eip155:10143\"}` in the body), in USDC (`0x534b2f3A21130d7a60830c2Df862319e593943A3`), paid to the payee `0x0C6239c982cE5B2db1D58b714259dc7B7455D501`."},{"intent":"charge","method":"evm","amount":"4000","currency":"0x534b2f3A21130d7a60830c2Df862319e593943A3","description":"US Treasury yield curves, 2015 to 2024: $40.00, paid as 0.004 USDC. MPP `evm` `charge`, credential `authorization` (EIP-3009), on Monad testnet (chain id 10143, `eip155:10143`, named `{\"network\": \"eip155:10143\"}` in the body), in USDC (`0x534b2f3A21130d7a60830c2Df862319e593943A3`), paid to the payee `0x0C6239c982cE5B2db1D58b714259dc7B7455D501`."},{"intent":"charge","method":"x402","amount":"4000","currency":"0x4fCF1784B31630811181f670Aea7A7bEF803eaED","description":"US Treasury yield curves, 2015 to 2024: $40.00, paid as 0.004 USDC. x402 `exact` on Sei testnet (`eip155:1328`, named `{\"network\": \"eip155:1328\"}` in the body), in USDC (`0x4fCF1784B31630811181f670Aea7A7bEF803eaED`), paid to the payee `0x0C6239c982cE5B2db1D58b714259dc7B7455D501`."},{"intent":"charge","method":"evm","amount":"4000","currency":"0x4fCF1784B31630811181f670Aea7A7bEF803eaED","description":"US Treasury yield curves, 2015 to 2024: $40.00, paid as 0.004 USDC. MPP `evm` `charge`, credential `authorization` (EIP-3009), on Sei testnet (chain id 1328, `eip155:1328`, named `{\"network\": \"eip155:1328\"}` in the body), in USDC (`0x4fCF1784B31630811181f670Aea7A7bEF803eaED`), paid to the payee `0x0C6239c982cE5B2db1D58b714259dc7B7455D501`."},{"intent":"charge","method":"x402","amount":"4000","currency":"0x0BA304580ee7c9a980CF72e55f5Ed2E9fd30Bc51","description":"US Treasury yield curves, 2015 to 2024: $40.00, paid as 0.004 USDC. x402 `exact` on Sonic testnet (`eip155:14601`, named `{\"network\": \"eip155:14601\"}` in the body), in USDC (`0x0BA304580ee7c9a980CF72e55f5Ed2E9fd30Bc51`), paid to the payee `0x0C6239c982cE5B2db1D58b714259dc7B7455D501`."},{"intent":"charge","method":"evm","amount":"4000","currency":"0x0BA304580ee7c9a980CF72e55f5Ed2E9fd30Bc51","description":"US Treasury yield curves, 2015 to 2024: $40.00, paid as 0.004 USDC. MPP `evm` `charge`, credential `authorization` (EIP-3009), on Sonic testnet (chain id 14601, `eip155:14601`, named `{\"network\": \"eip155:14601\"}` in the body), in USDC (`0x0BA304580ee7c9a980CF72e55f5Ed2E9fd30Bc51`), paid to the payee `0x0C6239c982cE5B2db1D58b714259dc7B7455D501`."},{"intent":"charge","method":"x402","amount":"4000","currency":"0x7433b41C6c5e1d58D4Da99483609520255ab661B","description":"US Treasury yield curves, 2015 to 2024: $40.00, paid as 0.004 USDC. x402 `exact` on Morph Hoodi (`eip155:2910`, named `{\"network\": \"eip155:2910\"}` in the body), in USDC (`0x7433b41C6c5e1d58D4Da99483609520255ab661B`), paid to the payee `0x0C6239c982cE5B2db1D58b714259dc7B7455D501`."},{"intent":"charge","method":"evm","amount":"4000","currency":"0x7433b41C6c5e1d58D4Da99483609520255ab661B","description":"US Treasury yield curves, 2015 to 2024: $40.00, paid as 0.004 USDC. MPP `evm` `charge`, credential `authorization` (EIP-3009), on Morph Hoodi (chain id 2910, `eip155:2910`, named `{\"network\": \"eip155:2910\"}` in the body), in USDC (`0x7433b41C6c5e1d58D4Da99483609520255ab661B`), paid to the payee `0x0C6239c982cE5B2db1D58b714259dc7B7455D501`."},{"intent":"charge","method":"x402","amount":"4000","currency":"0xEb33dc5fac03833e132593659e1dE7256aB59794","description":"US Treasury yield curves, 2015 to 2024: $40.00, paid as 0.004 USDC. x402 `exact` on Cronos testnet (`eip155:338`, named `{\"network\": \"eip155:338\"}` in the body), in USDC (`0xEb33dc5fac03833e132593659e1dE7256aB59794`), paid to the payee `0x0C6239c982cE5B2db1D58b714259dc7B7455D501`."},{"intent":"charge","method":"evm","amount":"4000","currency":"0xEb33dc5fac03833e132593659e1dE7256aB59794","description":"US Treasury yield curves, 2015 to 2024: $40.00, paid as 0.004 USDC. MPP `evm` `charge`, credential `authorization` (EIP-3009), on Cronos testnet (chain id 338, `eip155:338`, named `{\"network\": \"eip155:338\"}` in the body), in USDC (`0xEb33dc5fac03833e132593659e1dE7256aB59794`), paid to the payee `0x0C6239c982cE5B2db1D58b714259dc7B7455D501`."},{"intent":"charge","method":"x402","amount":"4000","currency":"0xcfC8330f4BCAB529c625D12781b1C19466A9Fc8B","description":"US Treasury yield curves, 2015 to 2024: $40.00, paid as 0.004 USDC. x402 `exact` on Pharos Atlantic (`eip155:688689`, named `{\"network\": \"eip155:688689\"}` in the body), in USDC (`0xcfC8330f4BCAB529c625D12781b1C19466A9Fc8B`), paid to the payee `0x0C6239c982cE5B2db1D58b714259dc7B7455D501`."},{"intent":"charge","method":"evm","amount":"4000","currency":"0xcfC8330f4BCAB529c625D12781b1C19466A9Fc8B","description":"US Treasury yield curves, 2015 to 2024: $40.00, paid as 0.004 USDC. MPP `evm` `charge`, credential `authorization` (EIP-3009), on Pharos Atlantic (chain id 688689, `eip155:688689`, named `{\"network\": \"eip155:688689\"}` in the body), in USDC (`0xcfC8330f4BCAB529c625D12781b1C19466A9Fc8B`), paid to the payee `0x0C6239c982cE5B2db1D58b714259dc7B7455D501`."}]},"responses":{"200":{"description":"Paid and delivered. `PAYMENT-RESPONSE` holds the x402 settlement, base64, or `Payment-Receipt` MPP's receipt, base64url, for a payment made with MPP; the body holds the delivery and the proof's address.","headers":{"PAYMENT-RESPONSE":{"schema":{"type":"string"}},"Payment-Receipt":{"schema":{"type":"string"}}}},"202":{"description":"The payment is sent and not yet confirmed. Send the same request again, or ask the proof's record."},"400":{"description":"Refused: the request lacks what the offer asks for, names a network this shop does not know, or names one this way of paying is never paid on, or is not as this operation says."},"402":{"description":"Payment required. `PAYMENT-REQUIRED` holds the x402 version 2 `PaymentRequired`, base64; the body holds it too. Its `extensions.legalContext.info` holds the agreement's hash H and its link: fetch the link, hash the bytes with SHA-256, and sign only if they match. Send the same request again with `PAYMENT-SIGNATURE`. The same answer carries MPP's challenge, `WWW-Authenticate: Payment … method=\"evm\", intent=\"charge\"`, for the same amount of the same token to the same payee, with an agreement of its own: its `opaque` (base64url JSON) holds `legalContext`, `lcp:sha256:` and that agreement's H, and `legalContextUrl`, its link. Check it the same way, and pay with `Authorization: Payment <credential>`, an `authorization` credential (EIP-3009) as `mppx` signs it. Pay one challenge, not both.","headers":{"PAYMENT-REQUIRED":{"schema":{"type":"string"}},"WWW-Authenticate":{"description":"MPP's `Payment` challenge, method `evm`, intent `charge`.","schema":{"type":"string"}}}},"502":{"description":"Paid, and not delivered: the seller tried again, and gave up. `PAYMENT-RESPONSE` holds the settlement, which succeeded; the body is the purchase."},"503":{"description":"Before a payment: the network named is not offered now, or the agreement could not be issued; nothing was taken. After a payment: paid, and not yet delivered, the seller tries again; `PAYMENT-RESPONSE` holds the settlement, which succeeded, `Retry-After` when to ask again, and the body is the purchase."}}}},"/buy/yield-curve-2024":{"get":{"operationId":"buy_yield_curve_2024","summary":"Buy US Treasury yield curves, 2024","description":"The 250 par yield curves the US Treasury published in 2024, one month to thirty years, as one CSV in the same columns as the ten-year file. $8.00, paid as 0.0008 USDC. Paid when bought (x402 `exact`). Paid by x402 or, on an EVM network, by MPP on the network the body's `network` names; a `GET` has no body, and is paid on `eip155:84532`. For demonstration only. This transaction runs on a test network with test money, and has no value.","parameters":[{"name":"PAYMENT-SIGNATURE","in":"header","required":false,"description":"The signed x402 payment, base64, on the request that repeats the one answered 402.","schema":{"type":"string"}}],"x-payment-info":{"offers":[{"intent":"charge","method":"x402","amount":"800","currency":"0x036CbD53842c5426634e7929541eC2318f3dCF7e","description":"US Treasury yield curves, 2024: $8.00, paid as 0.0008 USDC. x402 `exact` on Base Sepolia (`eip155:84532`, named `{\"network\": \"eip155:84532\"}` in the body, the default), in USDC (`0x036CbD53842c5426634e7929541eC2318f3dCF7e`), paid to the payee `0x0C6239c982cE5B2db1D58b714259dc7B7455D501`."},{"intent":"charge","method":"evm","amount":"800","currency":"0x036CbD53842c5426634e7929541eC2318f3dCF7e","description":"US Treasury yield curves, 2024: $8.00, paid as 0.0008 USDC. MPP `evm` `charge`, credential `authorization` (EIP-3009), on Base Sepolia (chain id 84532, `eip155:84532`, named `{\"network\": \"eip155:84532\"}` in the body, the default), in USDC (`0x036CbD53842c5426634e7929541eC2318f3dCF7e`), paid to the payee `0x0C6239c982cE5B2db1D58b714259dc7B7455D501`."},{"intent":"charge","method":"x402","amount":"800","currency":"0x3600000000000000000000000000000000000000","description":"US Treasury yield curves, 2024: $8.00, paid as 0.0008 USDC. x402 `exact` on Arc testnet (`eip155:5042002`, named `{\"network\": \"eip155:5042002\"}` in the body), in USDC (`0x3600000000000000000000000000000000000000`), paid to the payee `0x0C6239c982cE5B2db1D58b714259dc7B7455D501`."},{"intent":"charge","method":"evm","amount":"800","currency":"0x3600000000000000000000000000000000000000","description":"US Treasury yield curves, 2024: $8.00, paid as 0.0008 USDC. MPP `evm` `charge`, credential `authorization` (EIP-3009), on Arc testnet (chain id 5042002, `eip155:5042002`, named `{\"network\": \"eip155:5042002\"}` in the body), in USDC (`0x3600000000000000000000000000000000000000`), paid to the payee `0x0C6239c982cE5B2db1D58b714259dc7B7455D501`."},{"intent":"charge","method":"x402","amount":"800","currency":"0x5425890298aed601595a70AB815c96711a31Bc65","description":"US Treasury yield curves, 2024: $8.00, paid as 0.0008 USDC. x402 `exact` on Avalanche® Fuji (`eip155:43113`, named `{\"network\": \"eip155:43113\"}` in the body), in USDC (`0x5425890298aed601595a70AB815c96711a31Bc65`), paid to the payee `0x0C6239c982cE5B2db1D58b714259dc7B7455D501`."},{"intent":"charge","method":"evm","amount":"800","currency":"0x5425890298aed601595a70AB815c96711a31Bc65","description":"US Treasury yield curves, 2024: $8.00, paid as 0.0008 USDC. MPP `evm` `charge`, credential `authorization` (EIP-3009), on Avalanche® Fuji (chain id 43113, `eip155:43113`, named `{\"network\": \"eip155:43113\"}` in the body), in USDC (`0x5425890298aed601595a70AB815c96711a31Bc65`), paid to the payee `0x0C6239c982cE5B2db1D58b714259dc7B7455D501`."},{"intent":"charge","method":"x402","amount":"800","currency":"0.0.429274","description":"US Treasury yield curves, 2024: $8.00, paid as 0.0008 USDC. x402 `exact` on Hedera testnet (`hedera:testnet`, named `{\"network\": \"hedera:testnet\"}` in the body), in USDC (`0.0.429274`), paid to the payee `0.0.11173957`."},{"intent":"charge","method":"x402","amount":"8000","currency":"CBIELTK6YBZJU5UP2WWQEUCYKLPU6AUNZ2BQ4WWFEIE3USCIHMXQDAMA","description":"US Treasury yield curves, 2024: $8.00, paid as 0.0008 USDC. x402 `exact` on Stellar testnet (`stellar:testnet`, named `{\"network\": \"stellar:testnet\"}` in the body), in USDC (`CBIELTK6YBZJU5UP2WWQEUCYKLPU6AUNZ2BQ4WWFEIE3USCIHMXQDAMA`), paid to the payee `GCDGZBXG3PNUXEZWERCS7WE35QXUUYV4WD2AYAUD5A73QQG76LKRBLDY`."},{"intent":"charge","method":"x402","amount":"800","currency":"4zMMC9srt5Ri5X14GAgXhaHii3GnPAEERYPJgZJDncDU","description":"US Treasury yield curves, 2024: $8.00, paid as 0.0008 USDC. x402 `exact` on Solana devnet (`solana:EtWTRABZaYq6iMfeYKouRu166VU2xqa1`, named `{\"network\": \"solana:EtWTRABZaYq6iMfeYKouRu166VU2xqa1\"}` in the body), in USDC (`4zMMC9srt5Ri5X14GAgXhaHii3GnPAEERYPJgZJDncDU`), paid to the payee `7G32bRuk36oneaaZR5UNxUbithWzwqyGANCEm2KPn1D3`."},{"intent":"charge","method":"x402","amount":"800","currency":"5553444300000000000000000000000000000000","description":"US Treasury yield curves, 2024: $8.00, paid as 0.0008 USDC. x402 `exact` on XRPL Testnet (`xrpl:1`, named `{\"network\": \"xrpl:1\"}` in the body), in USDC (`5553444300000000000000000000000000000000`), paid to the payee `rP2TcSm1j65dFuDcJjFRvt4U2KXZryjdKi`."},{"intent":"charge","method":"x402","amount":"800","currency":"10458941","description":"US Treasury yield curves, 2024: $8.00, paid as 0.0008 USDC. x402 `exact` on Algorand testnet (`algorand:SGO1GKSzyE7IEPItTxCByw9x8FmnrCDe`, named `{\"network\": \"algorand:SGO1GKSzyE7IEPItTxCByw9x8FmnrCDe\"}` in the body), in USDC (`10458941`), paid to the payee `UQ6EUR44FU7ADT22WHVAIQS225PSBWD43PW5K3KKFCY6T6CKXNPKVPD5BA`."},{"intent":"charge","method":"x402","amount":"800","currency":"0x1c7D4B196Cb0C7B01d743Fbc6116a902379C7238","description":"US Treasury yield curves, 2024: $8.00, paid as 0.0008 USDC. x402 `exact` on Ethereum Sepolia (`eip155:11155111`, named `{\"network\": \"eip155:11155111\"}` in the body), in USDC (`0x1c7D4B196Cb0C7B01d743Fbc6116a902379C7238`), paid to the payee `0x0C6239c982cE5B2db1D58b714259dc7B7455D501`."},{"intent":"charge","method":"evm","amount":"800","currency":"0x1c7D4B196Cb0C7B01d743Fbc6116a902379C7238","description":"US Treasury yield curves, 2024: $8.00, paid as 0.0008 USDC. MPP `evm` `charge`, credential `authorization` (EIP-3009), on Ethereum Sepolia (chain id 11155111, `eip155:11155111`, named `{\"network\": \"eip155:11155111\"}` in the body), in USDC (`0x1c7D4B196Cb0C7B01d743Fbc6116a902379C7238`), paid to the payee `0x0C6239c982cE5B2db1D58b714259dc7B7455D501`."},{"intent":"charge","method":"x402","amount":"800","currency":"0x75faf114eafb1BDbe2F0316DF893fd58CE46AA4d","description":"US Treasury yield curves, 2024: $8.00, paid as 0.0008 USDC. x402 `exact` on Arbitrum Sepolia (`eip155:421614`, named `{\"network\": \"eip155:421614\"}` in the body), in USDC (`0x75faf114eafb1BDbe2F0316DF893fd58CE46AA4d`), paid to the payee `0x0C6239c982cE5B2db1D58b714259dc7B7455D501`."},{"intent":"charge","method":"evm","amount":"800","currency":"0x75faf114eafb1BDbe2F0316DF893fd58CE46AA4d","description":"US Treasury yield curves, 2024: $8.00, paid as 0.0008 USDC. MPP `evm` `charge`, credential `authorization` (EIP-3009), on Arbitrum Sepolia (chain id 421614, `eip155:421614`, named `{\"network\": \"eip155:421614\"}` in the body), in USDC (`0x75faf114eafb1BDbe2F0316DF893fd58CE46AA4d`), paid to the payee `0x0C6239c982cE5B2db1D58b714259dc7B7455D501`."},{"intent":"charge","method":"x402","amount":"800","currency":"0x5fd84259d66Cd46123540766Be93DFE6D43130D7","description":"US Treasury yield curves, 2024: $8.00, paid as 0.0008 USDC. x402 `exact` on OP Sepolia (`eip155:11155420`, named `{\"network\": \"eip155:11155420\"}` in the body), in USDC (`0x5fd84259d66Cd46123540766Be93DFE6D43130D7`), paid to the payee `0x0C6239c982cE5B2db1D58b714259dc7B7455D501`."},{"intent":"charge","method":"evm","amount":"800","currency":"0x5fd84259d66Cd46123540766Be93DFE6D43130D7","description":"US Treasury yield curves, 2024: $8.00, paid as 0.0008 USDC. MPP `evm` `charge`, credential `authorization` (EIP-3009), on OP Sepolia (chain id 11155420, `eip155:11155420`, named `{\"network\": \"eip155:11155420\"}` in the body), in USDC (`0x5fd84259d66Cd46123540766Be93DFE6D43130D7`), paid to the payee `0x0C6239c982cE5B2db1D58b714259dc7B7455D501`."},{"intent":"charge","method":"x402","amount":"800","currency":"0x41E94Eb019C0762f9Bfcf9Fb1E58725BfB0e7582","description":"US Treasury yield curves, 2024: $8.00, paid as 0.0008 USDC. x402 `exact` on Polygon Amoy (`eip155:80002`, named `{\"network\": \"eip155:80002\"}` in the body), in USDC (`0x41E94Eb019C0762f9Bfcf9Fb1E58725BfB0e7582`), paid to the payee `0x0C6239c982cE5B2db1D58b714259dc7B7455D501`."},{"intent":"charge","method":"evm","amount":"800","currency":"0x41E94Eb019C0762f9Bfcf9Fb1E58725BfB0e7582","description":"US Treasury yield curves, 2024: $8.00, paid as 0.0008 USDC. MPP `evm` `charge`, credential `authorization` (EIP-3009), on Polygon Amoy (chain id 80002, `eip155:80002`, named `{\"network\": \"eip155:80002\"}` in the body), in USDC (`0x41E94Eb019C0762f9Bfcf9Fb1E58725BfB0e7582`), paid to the payee `0x0C6239c982cE5B2db1D58b714259dc7B7455D501`."},{"intent":"charge","method":"x402","amount":"800","currency":"0x31d0220469e10c4E71834a79b1f276d740d3768F","description":"US Treasury yield curves, 2024: $8.00, paid as 0.0008 USDC. x402 `exact` on Unichain Sepolia (`eip155:1301`, named `{\"network\": \"eip155:1301\"}` in the body), in USDC (`0x31d0220469e10c4E71834a79b1f276d740d3768F`), paid to the payee `0x0C6239c982cE5B2db1D58b714259dc7B7455D501`."},{"intent":"charge","method":"evm","amount":"800","currency":"0x31d0220469e10c4E71834a79b1f276d740d3768F","description":"US Treasury yield curves, 2024: $8.00, paid as 0.0008 USDC. MPP `evm` `charge`, credential `authorization` (EIP-3009), on Unichain Sepolia (chain id 1301, `eip155:1301`, named `{\"network\": \"eip155:1301\"}` in the body), in USDC (`0x31d0220469e10c4E71834a79b1f276d740d3768F`), paid to the payee `0x0C6239c982cE5B2db1D58b714259dc7B7455D501`."},{"intent":"charge","method":"x402","amount":"800","currency":"0x66145f38cBAC35Ca6F1Dfb4914dF98F1614aeA88","description":"US Treasury yield curves, 2024: $8.00, paid as 0.0008 USDC. x402 `exact` on World Chain Sepolia (`eip155:4801`, named `{\"network\": \"eip155:4801\"}` in the body), in USDC (`0x66145f38cBAC35Ca6F1Dfb4914dF98F1614aeA88`), paid to the payee `0x0C6239c982cE5B2db1D58b714259dc7B7455D501`."},{"intent":"charge","method":"evm","amount":"800","currency":"0x66145f38cBAC35Ca6F1Dfb4914dF98F1614aeA88","description":"US Treasury yield curves, 2024: $8.00, paid as 0.0008 USDC. MPP `evm` `charge`, credential `authorization` (EIP-3009), on World Chain Sepolia (chain id 4801, `eip155:4801`, named `{\"network\": \"eip155:4801\"}` in the body), in USDC (`0x66145f38cBAC35Ca6F1Dfb4914dF98F1614aeA88`), paid to the payee `0x0C6239c982cE5B2db1D58b714259dc7B7455D501`."},{"intent":"charge","method":"x402","amount":"800","currency":"0xFabab97dCE620294D2B0b0e46C68964e326300Ac","description":"US Treasury yield curves, 2024: $8.00, paid as 0.0008 USDC. x402 `exact` on Ink Sepolia (`eip155:763373`, named `{\"network\": \"eip155:763373\"}` in the body), in USDC (`0xFabab97dCE620294D2B0b0e46C68964e326300Ac`), paid to the payee `0x0C6239c982cE5B2db1D58b714259dc7B7455D501`."},{"intent":"charge","method":"evm","amount":"800","currency":"0xFabab97dCE620294D2B0b0e46C68964e326300Ac","description":"US Treasury yield curves, 2024: $8.00, paid as 0.0008 USDC. MPP `evm` `charge`, credential `authorization` (EIP-3009), on Ink Sepolia (chain id 763373, `eip155:763373`, named `{\"network\": \"eip155:763373\"}` in the body), in USDC (`0xFabab97dCE620294D2B0b0e46C68964e326300Ac`), paid to the payee `0x0C6239c982cE5B2db1D58b714259dc7B7455D501`."},{"intent":"charge","method":"x402","amount":"800","currency":"0x01C5C0122039549AD1493B8220cABEdD739BC44E","description":"US Treasury yield curves, 2024: $8.00, paid as 0.0008 USDC. x402 `exact` on Celo Sepolia (`eip155:11142220`, named `{\"network\": \"eip155:11142220\"}` in the body), in USDC (`0x01C5C0122039549AD1493B8220cABEdD739BC44E`), paid to the payee `0x0C6239c982cE5B2db1D58b714259dc7B7455D501`."},{"intent":"charge","method":"evm","amount":"800","currency":"0x01C5C0122039549AD1493B8220cABEdD739BC44E","description":"US Treasury yield curves, 2024: $8.00, paid as 0.0008 USDC. MPP `evm` `charge`, credential `authorization` (EIP-3009), on Celo Sepolia (chain id 11142220, `eip155:11142220`, named `{\"network\": \"eip155:11142220\"}` in the body), in USDC (`0x01C5C0122039549AD1493B8220cABEdD739BC44E`), paid to the payee `0x0C6239c982cE5B2db1D58b714259dc7B7455D501`."},{"intent":"charge","method":"x402","amount":"800","currency":"0x534b2f3A21130d7a60830c2Df862319e593943A3","description":"US Treasury yield curves, 2024: $8.00, paid as 0.0008 USDC. x402 `exact` on Monad testnet (`eip155:10143`, named `{\"network\": \"eip155:10143\"}` in the body), in USDC (`0x534b2f3A21130d7a60830c2Df862319e593943A3`), paid to the payee `0x0C6239c982cE5B2db1D58b714259dc7B7455D501`."},{"intent":"charge","method":"evm","amount":"800","currency":"0x534b2f3A21130d7a60830c2Df862319e593943A3","description":"US Treasury yield curves, 2024: $8.00, paid as 0.0008 USDC. MPP `evm` `charge`, credential `authorization` (EIP-3009), on Monad testnet (chain id 10143, `eip155:10143`, named `{\"network\": \"eip155:10143\"}` in the body), in USDC (`0x534b2f3A21130d7a60830c2Df862319e593943A3`), paid to the payee `0x0C6239c982cE5B2db1D58b714259dc7B7455D501`."},{"intent":"charge","method":"x402","amount":"800","currency":"0x4fCF1784B31630811181f670Aea7A7bEF803eaED","description":"US Treasury yield curves, 2024: $8.00, paid as 0.0008 USDC. x402 `exact` on Sei testnet (`eip155:1328`, named `{\"network\": \"eip155:1328\"}` in the body), in USDC (`0x4fCF1784B31630811181f670Aea7A7bEF803eaED`), paid to the payee `0x0C6239c982cE5B2db1D58b714259dc7B7455D501`."},{"intent":"charge","method":"evm","amount":"800","currency":"0x4fCF1784B31630811181f670Aea7A7bEF803eaED","description":"US Treasury yield curves, 2024: $8.00, paid as 0.0008 USDC. MPP `evm` `charge`, credential `authorization` (EIP-3009), on Sei testnet (chain id 1328, `eip155:1328`, named `{\"network\": \"eip155:1328\"}` in the body), in USDC (`0x4fCF1784B31630811181f670Aea7A7bEF803eaED`), paid to the payee `0x0C6239c982cE5B2db1D58b714259dc7B7455D501`."},{"intent":"charge","method":"x402","amount":"800","currency":"0x0BA304580ee7c9a980CF72e55f5Ed2E9fd30Bc51","description":"US Treasury yield curves, 2024: $8.00, paid as 0.0008 USDC. x402 `exact` on Sonic testnet (`eip155:14601`, named `{\"network\": \"eip155:14601\"}` in the body), in USDC (`0x0BA304580ee7c9a980CF72e55f5Ed2E9fd30Bc51`), paid to the payee `0x0C6239c982cE5B2db1D58b714259dc7B7455D501`."},{"intent":"charge","method":"evm","amount":"800","currency":"0x0BA304580ee7c9a980CF72e55f5Ed2E9fd30Bc51","description":"US Treasury yield curves, 2024: $8.00, paid as 0.0008 USDC. MPP `evm` `charge`, credential `authorization` (EIP-3009), on Sonic testnet (chain id 14601, `eip155:14601`, named `{\"network\": \"eip155:14601\"}` in the body), in USDC (`0x0BA304580ee7c9a980CF72e55f5Ed2E9fd30Bc51`), paid to the payee `0x0C6239c982cE5B2db1D58b714259dc7B7455D501`."},{"intent":"charge","method":"x402","amount":"800","currency":"0x7433b41C6c5e1d58D4Da99483609520255ab661B","description":"US Treasury yield curves, 2024: $8.00, paid as 0.0008 USDC. x402 `exact` on Morph Hoodi (`eip155:2910`, named `{\"network\": \"eip155:2910\"}` in the body), in USDC (`0x7433b41C6c5e1d58D4Da99483609520255ab661B`), paid to the payee `0x0C6239c982cE5B2db1D58b714259dc7B7455D501`."},{"intent":"charge","method":"evm","amount":"800","currency":"0x7433b41C6c5e1d58D4Da99483609520255ab661B","description":"US Treasury yield curves, 2024: $8.00, paid as 0.0008 USDC. MPP `evm` `charge`, credential `authorization` (EIP-3009), on Morph Hoodi (chain id 2910, `eip155:2910`, named `{\"network\": \"eip155:2910\"}` in the body), in USDC (`0x7433b41C6c5e1d58D4Da99483609520255ab661B`), paid to the payee `0x0C6239c982cE5B2db1D58b714259dc7B7455D501`."},{"intent":"charge","method":"x402","amount":"800","currency":"0xEb33dc5fac03833e132593659e1dE7256aB59794","description":"US Treasury yield curves, 2024: $8.00, paid as 0.0008 USDC. x402 `exact` on Cronos testnet (`eip155:338`, named `{\"network\": \"eip155:338\"}` in the body), in USDC (`0xEb33dc5fac03833e132593659e1dE7256aB59794`), paid to the payee `0x0C6239c982cE5B2db1D58b714259dc7B7455D501`."},{"intent":"charge","method":"evm","amount":"800","currency":"0xEb33dc5fac03833e132593659e1dE7256aB59794","description":"US Treasury yield curves, 2024: $8.00, paid as 0.0008 USDC. MPP `evm` `charge`, credential `authorization` (EIP-3009), on Cronos testnet (chain id 338, `eip155:338`, named `{\"network\": \"eip155:338\"}` in the body), in USDC (`0xEb33dc5fac03833e132593659e1dE7256aB59794`), paid to the payee `0x0C6239c982cE5B2db1D58b714259dc7B7455D501`."},{"intent":"charge","method":"x402","amount":"800","currency":"0xcfC8330f4BCAB529c625D12781b1C19466A9Fc8B","description":"US Treasury yield curves, 2024: $8.00, paid as 0.0008 USDC. x402 `exact` on Pharos Atlantic (`eip155:688689`, named `{\"network\": \"eip155:688689\"}` in the body), in USDC (`0xcfC8330f4BCAB529c625D12781b1C19466A9Fc8B`), paid to the payee `0x0C6239c982cE5B2db1D58b714259dc7B7455D501`."},{"intent":"charge","method":"evm","amount":"800","currency":"0xcfC8330f4BCAB529c625D12781b1C19466A9Fc8B","description":"US Treasury yield curves, 2024: $8.00, paid as 0.0008 USDC. MPP `evm` `charge`, credential `authorization` (EIP-3009), on Pharos Atlantic (chain id 688689, `eip155:688689`, named `{\"network\": \"eip155:688689\"}` in the body), in USDC (`0xcfC8330f4BCAB529c625D12781b1C19466A9Fc8B`), paid to the payee `0x0C6239c982cE5B2db1D58b714259dc7B7455D501`."}]},"responses":{"200":{"description":"Paid and delivered. `PAYMENT-RESPONSE` holds the x402 settlement, base64, or `Payment-Receipt` MPP's receipt, base64url, for a payment made with MPP; the body holds the delivery and the proof's address.","headers":{"PAYMENT-RESPONSE":{"schema":{"type":"string"}},"Payment-Receipt":{"schema":{"type":"string"}}}},"202":{"description":"The payment is sent and not yet confirmed. Send the same request again, or ask the proof's record."},"400":{"description":"Refused: the request lacks what the offer asks for, names a network this shop does not know, or names one this way of paying is never paid on, or is not as this operation says."},"402":{"description":"Payment required. `PAYMENT-REQUIRED` holds the x402 version 2 `PaymentRequired`, base64; the body holds it too. Its `extensions.legalContext.info` holds the agreement's hash H and its link: fetch the link, hash the bytes with SHA-256, and sign only if they match. Send the same request again with `PAYMENT-SIGNATURE`. The same answer carries MPP's challenge, `WWW-Authenticate: Payment … method=\"evm\", intent=\"charge\"`, for the same amount of the same token to the same payee, with an agreement of its own: its `opaque` (base64url JSON) holds `legalContext`, `lcp:sha256:` and that agreement's H, and `legalContextUrl`, its link. Check it the same way, and pay with `Authorization: Payment <credential>`, an `authorization` credential (EIP-3009) as `mppx` signs it. Pay one challenge, not both.","headers":{"PAYMENT-REQUIRED":{"schema":{"type":"string"}},"WWW-Authenticate":{"description":"MPP's `Payment` challenge, method `evm`, intent `charge`.","schema":{"type":"string"}}}},"502":{"description":"Paid, and not delivered: the seller tried again, and gave up. `PAYMENT-RESPONSE` holds the settlement, which succeeded; the body is the purchase."},"503":{"description":"Before a payment: the network named is not offered now, or the agreement could not be issued; nothing was taken. After a payment: paid, and not yet delivered, the seller tries again; `PAYMENT-RESPONSE` holds the settlement, which succeeded, `Retry-After` when to ask again, and the body is the purchase."}}},"post":{"operationId":"buy_yield_curve_2024_post","summary":"Buy US Treasury yield curves, 2024","description":"The 250 par yield curves the US Treasury published in 2024, one month to thirty years, as one CSV in the same columns as the ten-year file. $8.00, paid as 0.0008 USDC. Paid when bought (x402 `exact`). Paid by x402 or, on an EVM network, by MPP on the network the body's `network` names. For demonstration only. This transaction runs on a test network with test money, and has no value.","parameters":[{"name":"PAYMENT-SIGNATURE","in":"header","required":false,"description":"The signed x402 payment, base64, on the request that repeats the one answered 402.","schema":{"type":"string"}}],"requestBody":{"required":false,"content":{"application/json":{"schema":{"type":"object","additionalProperties":false,"required":[],"properties":{"network":{"type":"string","enum":["eip155:84532","eip155:5042002","eip155:43113","hedera:testnet","stellar:testnet","solana:EtWTRABZaYq6iMfeYKouRu166VU2xqa1","xrpl:1","algorand:SGO1GKSzyE7IEPItTxCByw9x8FmnrCDe","eip155:11155111","eip155:421614","eip155:11155420","eip155:80002","eip155:1301","eip155:4801","eip155:763373","eip155:11142220","eip155:10143","eip155:1328","eip155:14601","eip155:2910","eip155:338","eip155:688689"],"description":"The network the checkout is paid on, a CAIP-2 id; without it, `eip155:84532`. The paid request repeats it, as it repeats the whole request."}}},"example":{}}}},"x-payment-info":{"offers":[{"intent":"charge","method":"x402","amount":"800","currency":"0x036CbD53842c5426634e7929541eC2318f3dCF7e","description":"US Treasury yield curves, 2024: $8.00, paid as 0.0008 USDC. x402 `exact` on Base Sepolia (`eip155:84532`, named `{\"network\": \"eip155:84532\"}` in the body, the default), in USDC (`0x036CbD53842c5426634e7929541eC2318f3dCF7e`), paid to the payee `0x0C6239c982cE5B2db1D58b714259dc7B7455D501`."},{"intent":"charge","method":"evm","amount":"800","currency":"0x036CbD53842c5426634e7929541eC2318f3dCF7e","description":"US Treasury yield curves, 2024: $8.00, paid as 0.0008 USDC. MPP `evm` `charge`, credential `authorization` (EIP-3009), on Base Sepolia (chain id 84532, `eip155:84532`, named `{\"network\": \"eip155:84532\"}` in the body, the default), in USDC (`0x036CbD53842c5426634e7929541eC2318f3dCF7e`), paid to the payee `0x0C6239c982cE5B2db1D58b714259dc7B7455D501`."},{"intent":"charge","method":"x402","amount":"800","currency":"0x3600000000000000000000000000000000000000","description":"US Treasury yield curves, 2024: $8.00, paid as 0.0008 USDC. x402 `exact` on Arc testnet (`eip155:5042002`, named `{\"network\": \"eip155:5042002\"}` in the body), in USDC (`0x3600000000000000000000000000000000000000`), paid to the payee `0x0C6239c982cE5B2db1D58b714259dc7B7455D501`."},{"intent":"charge","method":"evm","amount":"800","currency":"0x3600000000000000000000000000000000000000","description":"US Treasury yield curves, 2024: $8.00, paid as 0.0008 USDC. MPP `evm` `charge`, credential `authorization` (EIP-3009), on Arc testnet (chain id 5042002, `eip155:5042002`, named `{\"network\": \"eip155:5042002\"}` in the body), in USDC (`0x3600000000000000000000000000000000000000`), paid to the payee `0x0C6239c982cE5B2db1D58b714259dc7B7455D501`."},{"intent":"charge","method":"x402","amount":"800","currency":"0x5425890298aed601595a70AB815c96711a31Bc65","description":"US Treasury yield curves, 2024: $8.00, paid as 0.0008 USDC. x402 `exact` on Avalanche® Fuji (`eip155:43113`, named `{\"network\": \"eip155:43113\"}` in the body), in USDC (`0x5425890298aed601595a70AB815c96711a31Bc65`), paid to the payee `0x0C6239c982cE5B2db1D58b714259dc7B7455D501`."},{"intent":"charge","method":"evm","amount":"800","currency":"0x5425890298aed601595a70AB815c96711a31Bc65","description":"US Treasury yield curves, 2024: $8.00, paid as 0.0008 USDC. MPP `evm` `charge`, credential `authorization` (EIP-3009), on Avalanche® Fuji (chain id 43113, `eip155:43113`, named `{\"network\": \"eip155:43113\"}` in the body), in USDC (`0x5425890298aed601595a70AB815c96711a31Bc65`), paid to the payee `0x0C6239c982cE5B2db1D58b714259dc7B7455D501`."},{"intent":"charge","method":"x402","amount":"800","currency":"0.0.429274","description":"US Treasury yield curves, 2024: $8.00, paid as 0.0008 USDC. x402 `exact` on Hedera testnet (`hedera:testnet`, named `{\"network\": \"hedera:testnet\"}` in the body), in USDC (`0.0.429274`), paid to the payee `0.0.11173957`."},{"intent":"charge","method":"x402","amount":"8000","currency":"CBIELTK6YBZJU5UP2WWQEUCYKLPU6AUNZ2BQ4WWFEIE3USCIHMXQDAMA","description":"US Treasury yield curves, 2024: $8.00, paid as 0.0008 USDC. x402 `exact` on Stellar testnet (`stellar:testnet`, named `{\"network\": \"stellar:testnet\"}` in the body), in USDC (`CBIELTK6YBZJU5UP2WWQEUCYKLPU6AUNZ2BQ4WWFEIE3USCIHMXQDAMA`), paid to the payee `GCDGZBXG3PNUXEZWERCS7WE35QXUUYV4WD2AYAUD5A73QQG76LKRBLDY`."},{"intent":"charge","method":"x402","amount":"800","currency":"4zMMC9srt5Ri5X14GAgXhaHii3GnPAEERYPJgZJDncDU","description":"US Treasury yield curves, 2024: $8.00, paid as 0.0008 USDC. x402 `exact` on Solana devnet (`solana:EtWTRABZaYq6iMfeYKouRu166VU2xqa1`, named `{\"network\": \"solana:EtWTRABZaYq6iMfeYKouRu166VU2xqa1\"}` in the body), in USDC (`4zMMC9srt5Ri5X14GAgXhaHii3GnPAEERYPJgZJDncDU`), paid to the payee `7G32bRuk36oneaaZR5UNxUbithWzwqyGANCEm2KPn1D3`."},{"intent":"charge","method":"x402","amount":"800","currency":"5553444300000000000000000000000000000000","description":"US Treasury yield curves, 2024: $8.00, paid as 0.0008 USDC. x402 `exact` on XRPL Testnet (`xrpl:1`, named `{\"network\": \"xrpl:1\"}` in the body), in USDC (`5553444300000000000000000000000000000000`), paid to the payee `rP2TcSm1j65dFuDcJjFRvt4U2KXZryjdKi`."},{"intent":"charge","method":"x402","amount":"800","currency":"10458941","description":"US Treasury yield curves, 2024: $8.00, paid as 0.0008 USDC. x402 `exact` on Algorand testnet (`algorand:SGO1GKSzyE7IEPItTxCByw9x8FmnrCDe`, named `{\"network\": \"algorand:SGO1GKSzyE7IEPItTxCByw9x8FmnrCDe\"}` in the body), in USDC (`10458941`), paid to the payee `UQ6EUR44FU7ADT22WHVAIQS225PSBWD43PW5K3KKFCY6T6CKXNPKVPD5BA`."},{"intent":"charge","method":"x402","amount":"800","currency":"0x1c7D4B196Cb0C7B01d743Fbc6116a902379C7238","description":"US Treasury yield curves, 2024: $8.00, paid as 0.0008 USDC. x402 `exact` on Ethereum Sepolia (`eip155:11155111`, named `{\"network\": \"eip155:11155111\"}` in the body), in USDC (`0x1c7D4B196Cb0C7B01d743Fbc6116a902379C7238`), paid to the payee `0x0C6239c982cE5B2db1D58b714259dc7B7455D501`."},{"intent":"charge","method":"evm","amount":"800","currency":"0x1c7D4B196Cb0C7B01d743Fbc6116a902379C7238","description":"US Treasury yield curves, 2024: $8.00, paid as 0.0008 USDC. MPP `evm` `charge`, credential `authorization` (EIP-3009), on Ethereum Sepolia (chain id 11155111, `eip155:11155111`, named `{\"network\": \"eip155:11155111\"}` in the body), in USDC (`0x1c7D4B196Cb0C7B01d743Fbc6116a902379C7238`), paid to the payee `0x0C6239c982cE5B2db1D58b714259dc7B7455D501`."},{"intent":"charge","method":"x402","amount":"800","currency":"0x75faf114eafb1BDbe2F0316DF893fd58CE46AA4d","description":"US Treasury yield curves, 2024: $8.00, paid as 0.0008 USDC. x402 `exact` on Arbitrum Sepolia (`eip155:421614`, named `{\"network\": \"eip155:421614\"}` in the body), in USDC (`0x75faf114eafb1BDbe2F0316DF893fd58CE46AA4d`), paid to the payee `0x0C6239c982cE5B2db1D58b714259dc7B7455D501`."},{"intent":"charge","method":"evm","amount":"800","currency":"0x75faf114eafb1BDbe2F0316DF893fd58CE46AA4d","description":"US Treasury yield curves, 2024: $8.00, paid as 0.0008 USDC. MPP `evm` `charge`, credential `authorization` (EIP-3009), on Arbitrum Sepolia (chain id 421614, `eip155:421614`, named `{\"network\": \"eip155:421614\"}` in the body), in USDC (`0x75faf114eafb1BDbe2F0316DF893fd58CE46AA4d`), paid to the payee `0x0C6239c982cE5B2db1D58b714259dc7B7455D501`."},{"intent":"charge","method":"x402","amount":"800","currency":"0x5fd84259d66Cd46123540766Be93DFE6D43130D7","description":"US Treasury yield curves, 2024: $8.00, paid as 0.0008 USDC. x402 `exact` on OP Sepolia (`eip155:11155420`, named `{\"network\": \"eip155:11155420\"}` in the body), in USDC (`0x5fd84259d66Cd46123540766Be93DFE6D43130D7`), paid to the payee `0x0C6239c982cE5B2db1D58b714259dc7B7455D501`."},{"intent":"charge","method":"evm","amount":"800","currency":"0x5fd84259d66Cd46123540766Be93DFE6D43130D7","description":"US Treasury yield curves, 2024: $8.00, paid as 0.0008 USDC. MPP `evm` `charge`, credential `authorization` (EIP-3009), on OP Sepolia (chain id 11155420, `eip155:11155420`, named `{\"network\": \"eip155:11155420\"}` in the body), in USDC (`0x5fd84259d66Cd46123540766Be93DFE6D43130D7`), paid to the payee `0x0C6239c982cE5B2db1D58b714259dc7B7455D501`."},{"intent":"charge","method":"x402","amount":"800","currency":"0x41E94Eb019C0762f9Bfcf9Fb1E58725BfB0e7582","description":"US Treasury yield curves, 2024: $8.00, paid as 0.0008 USDC. x402 `exact` on Polygon Amoy (`eip155:80002`, named `{\"network\": \"eip155:80002\"}` in the body), in USDC (`0x41E94Eb019C0762f9Bfcf9Fb1E58725BfB0e7582`), paid to the payee `0x0C6239c982cE5B2db1D58b714259dc7B7455D501`."},{"intent":"charge","method":"evm","amount":"800","currency":"0x41E94Eb019C0762f9Bfcf9Fb1E58725BfB0e7582","description":"US Treasury yield curves, 2024: $8.00, paid as 0.0008 USDC. MPP `evm` `charge`, credential `authorization` (EIP-3009), on Polygon Amoy (chain id 80002, `eip155:80002`, named `{\"network\": \"eip155:80002\"}` in the body), in USDC (`0x41E94Eb019C0762f9Bfcf9Fb1E58725BfB0e7582`), paid to the payee `0x0C6239c982cE5B2db1D58b714259dc7B7455D501`."},{"intent":"charge","method":"x402","amount":"800","currency":"0x31d0220469e10c4E71834a79b1f276d740d3768F","description":"US Treasury yield curves, 2024: $8.00, paid as 0.0008 USDC. x402 `exact` on Unichain Sepolia (`eip155:1301`, named `{\"network\": \"eip155:1301\"}` in the body), in USDC (`0x31d0220469e10c4E71834a79b1f276d740d3768F`), paid to the payee `0x0C6239c982cE5B2db1D58b714259dc7B7455D501`."},{"intent":"charge","method":"evm","amount":"800","currency":"0x31d0220469e10c4E71834a79b1f276d740d3768F","description":"US Treasury yield curves, 2024: $8.00, paid as 0.0008 USDC. MPP `evm` `charge`, credential `authorization` (EIP-3009), on Unichain Sepolia (chain id 1301, `eip155:1301`, named `{\"network\": \"eip155:1301\"}` in the body), in USDC (`0x31d0220469e10c4E71834a79b1f276d740d3768F`), paid to the payee `0x0C6239c982cE5B2db1D58b714259dc7B7455D501`."},{"intent":"charge","method":"x402","amount":"800","currency":"0x66145f38cBAC35Ca6F1Dfb4914dF98F1614aeA88","description":"US Treasury yield curves, 2024: $8.00, paid as 0.0008 USDC. x402 `exact` on World Chain Sepolia (`eip155:4801`, named `{\"network\": \"eip155:4801\"}` in the body), in USDC (`0x66145f38cBAC35Ca6F1Dfb4914dF98F1614aeA88`), paid to the payee `0x0C6239c982cE5B2db1D58b714259dc7B7455D501`."},{"intent":"charge","method":"evm","amount":"800","currency":"0x66145f38cBAC35Ca6F1Dfb4914dF98F1614aeA88","description":"US Treasury yield curves, 2024: $8.00, paid as 0.0008 USDC. MPP `evm` `charge`, credential `authorization` (EIP-3009), on World Chain Sepolia (chain id 4801, `eip155:4801`, named `{\"network\": \"eip155:4801\"}` in the body), in USDC (`0x66145f38cBAC35Ca6F1Dfb4914dF98F1614aeA88`), paid to the payee `0x0C6239c982cE5B2db1D58b714259dc7B7455D501`."},{"intent":"charge","method":"x402","amount":"800","currency":"0xFabab97dCE620294D2B0b0e46C68964e326300Ac","description":"US Treasury yield curves, 2024: $8.00, paid as 0.0008 USDC. x402 `exact` on Ink Sepolia (`eip155:763373`, named `{\"network\": \"eip155:763373\"}` in the body), in USDC (`0xFabab97dCE620294D2B0b0e46C68964e326300Ac`), paid to the payee `0x0C6239c982cE5B2db1D58b714259dc7B7455D501`."},{"intent":"charge","method":"evm","amount":"800","currency":"0xFabab97dCE620294D2B0b0e46C68964e326300Ac","description":"US Treasury yield curves, 2024: $8.00, paid as 0.0008 USDC. MPP `evm` `charge`, credential `authorization` (EIP-3009), on Ink Sepolia (chain id 763373, `eip155:763373`, named `{\"network\": \"eip155:763373\"}` in the body), in USDC (`0xFabab97dCE620294D2B0b0e46C68964e326300Ac`), paid to the payee `0x0C6239c982cE5B2db1D58b714259dc7B7455D501`."},{"intent":"charge","method":"x402","amount":"800","currency":"0x01C5C0122039549AD1493B8220cABEdD739BC44E","description":"US Treasury yield curves, 2024: $8.00, paid as 0.0008 USDC. x402 `exact` on Celo Sepolia (`eip155:11142220`, named `{\"network\": \"eip155:11142220\"}` in the body), in USDC (`0x01C5C0122039549AD1493B8220cABEdD739BC44E`), paid to the payee `0x0C6239c982cE5B2db1D58b714259dc7B7455D501`."},{"intent":"charge","method":"evm","amount":"800","currency":"0x01C5C0122039549AD1493B8220cABEdD739BC44E","description":"US Treasury yield curves, 2024: $8.00, paid as 0.0008 USDC. MPP `evm` `charge`, credential `authorization` (EIP-3009), on Celo Sepolia (chain id 11142220, `eip155:11142220`, named `{\"network\": \"eip155:11142220\"}` in the body), in USDC (`0x01C5C0122039549AD1493B8220cABEdD739BC44E`), paid to the payee `0x0C6239c982cE5B2db1D58b714259dc7B7455D501`."},{"intent":"charge","method":"x402","amount":"800","currency":"0x534b2f3A21130d7a60830c2Df862319e593943A3","description":"US Treasury yield curves, 2024: $8.00, paid as 0.0008 USDC. x402 `exact` on Monad testnet (`eip155:10143`, named `{\"network\": \"eip155:10143\"}` in the body), in USDC (`0x534b2f3A21130d7a60830c2Df862319e593943A3`), paid to the payee `0x0C6239c982cE5B2db1D58b714259dc7B7455D501`."},{"intent":"charge","method":"evm","amount":"800","currency":"0x534b2f3A21130d7a60830c2Df862319e593943A3","description":"US Treasury yield curves, 2024: $8.00, paid as 0.0008 USDC. MPP `evm` `charge`, credential `authorization` (EIP-3009), on Monad testnet (chain id 10143, `eip155:10143`, named `{\"network\": \"eip155:10143\"}` in the body), in USDC (`0x534b2f3A21130d7a60830c2Df862319e593943A3`), paid to the payee `0x0C6239c982cE5B2db1D58b714259dc7B7455D501`."},{"intent":"charge","method":"x402","amount":"800","currency":"0x4fCF1784B31630811181f670Aea7A7bEF803eaED","description":"US Treasury yield curves, 2024: $8.00, paid as 0.0008 USDC. x402 `exact` on Sei testnet (`eip155:1328`, named `{\"network\": \"eip155:1328\"}` in the body), in USDC (`0x4fCF1784B31630811181f670Aea7A7bEF803eaED`), paid to the payee `0x0C6239c982cE5B2db1D58b714259dc7B7455D501`."},{"intent":"charge","method":"evm","amount":"800","currency":"0x4fCF1784B31630811181f670Aea7A7bEF803eaED","description":"US Treasury yield curves, 2024: $8.00, paid as 0.0008 USDC. MPP `evm` `charge`, credential `authorization` (EIP-3009), on Sei testnet (chain id 1328, `eip155:1328`, named `{\"network\": \"eip155:1328\"}` in the body), in USDC (`0x4fCF1784B31630811181f670Aea7A7bEF803eaED`), paid to the payee `0x0C6239c982cE5B2db1D58b714259dc7B7455D501`."},{"intent":"charge","method":"x402","amount":"800","currency":"0x0BA304580ee7c9a980CF72e55f5Ed2E9fd30Bc51","description":"US Treasury yield curves, 2024: $8.00, paid as 0.0008 USDC. x402 `exact` on Sonic testnet (`eip155:14601`, named `{\"network\": \"eip155:14601\"}` in the body), in USDC (`0x0BA304580ee7c9a980CF72e55f5Ed2E9fd30Bc51`), paid to the payee `0x0C6239c982cE5B2db1D58b714259dc7B7455D501`."},{"intent":"charge","method":"evm","amount":"800","currency":"0x0BA304580ee7c9a980CF72e55f5Ed2E9fd30Bc51","description":"US Treasury yield curves, 2024: $8.00, paid as 0.0008 USDC. MPP `evm` `charge`, credential `authorization` (EIP-3009), on Sonic testnet (chain id 14601, `eip155:14601`, named `{\"network\": \"eip155:14601\"}` in the body), in USDC (`0x0BA304580ee7c9a980CF72e55f5Ed2E9fd30Bc51`), paid to the payee `0x0C6239c982cE5B2db1D58b714259dc7B7455D501`."},{"intent":"charge","method":"x402","amount":"800","currency":"0x7433b41C6c5e1d58D4Da99483609520255ab661B","description":"US Treasury yield curves, 2024: $8.00, paid as 0.0008 USDC. x402 `exact` on Morph Hoodi (`eip155:2910`, named `{\"network\": \"eip155:2910\"}` in the body), in USDC (`0x7433b41C6c5e1d58D4Da99483609520255ab661B`), paid to the payee `0x0C6239c982cE5B2db1D58b714259dc7B7455D501`."},{"intent":"charge","method":"evm","amount":"800","currency":"0x7433b41C6c5e1d58D4Da99483609520255ab661B","description":"US Treasury yield curves, 2024: $8.00, paid as 0.0008 USDC. MPP `evm` `charge`, credential `authorization` (EIP-3009), on Morph Hoodi (chain id 2910, `eip155:2910`, named `{\"network\": \"eip155:2910\"}` in the body), in USDC (`0x7433b41C6c5e1d58D4Da99483609520255ab661B`), paid to the payee `0x0C6239c982cE5B2db1D58b714259dc7B7455D501`."},{"intent":"charge","method":"x402","amount":"800","currency":"0xEb33dc5fac03833e132593659e1dE7256aB59794","description":"US Treasury yield curves, 2024: $8.00, paid as 0.0008 USDC. x402 `exact` on Cronos testnet (`eip155:338`, named `{\"network\": \"eip155:338\"}` in the body), in USDC (`0xEb33dc5fac03833e132593659e1dE7256aB59794`), paid to the payee `0x0C6239c982cE5B2db1D58b714259dc7B7455D501`."},{"intent":"charge","method":"evm","amount":"800","currency":"0xEb33dc5fac03833e132593659e1dE7256aB59794","description":"US Treasury yield curves, 2024: $8.00, paid as 0.0008 USDC. MPP `evm` `charge`, credential `authorization` (EIP-3009), on Cronos testnet (chain id 338, `eip155:338`, named `{\"network\": \"eip155:338\"}` in the body), in USDC (`0xEb33dc5fac03833e132593659e1dE7256aB59794`), paid to the payee `0x0C6239c982cE5B2db1D58b714259dc7B7455D501`."},{"intent":"charge","method":"x402","amount":"800","currency":"0xcfC8330f4BCAB529c625D12781b1C19466A9Fc8B","description":"US Treasury yield curves, 2024: $8.00, paid as 0.0008 USDC. x402 `exact` on Pharos Atlantic (`eip155:688689`, named `{\"network\": \"eip155:688689\"}` in the body), in USDC (`0xcfC8330f4BCAB529c625D12781b1C19466A9Fc8B`), paid to the payee `0x0C6239c982cE5B2db1D58b714259dc7B7455D501`."},{"intent":"charge","method":"evm","amount":"800","currency":"0xcfC8330f4BCAB529c625D12781b1C19466A9Fc8B","description":"US Treasury yield curves, 2024: $8.00, paid as 0.0008 USDC. MPP `evm` `charge`, credential `authorization` (EIP-3009), on Pharos Atlantic (chain id 688689, `eip155:688689`, named `{\"network\": \"eip155:688689\"}` in the body), in USDC (`0xcfC8330f4BCAB529c625D12781b1C19466A9Fc8B`), paid to the payee `0x0C6239c982cE5B2db1D58b714259dc7B7455D501`."}]},"responses":{"200":{"description":"Paid and delivered. `PAYMENT-RESPONSE` holds the x402 settlement, base64, or `Payment-Receipt` MPP's receipt, base64url, for a payment made with MPP; the body holds the delivery and the proof's address.","headers":{"PAYMENT-RESPONSE":{"schema":{"type":"string"}},"Payment-Receipt":{"schema":{"type":"string"}}}},"202":{"description":"The payment is sent and not yet confirmed. Send the same request again, or ask the proof's record."},"400":{"description":"Refused: the request lacks what the offer asks for, names a network this shop does not know, or names one this way of paying is never paid on, or is not as this operation says."},"402":{"description":"Payment required. `PAYMENT-REQUIRED` holds the x402 version 2 `PaymentRequired`, base64; the body holds it too. Its `extensions.legalContext.info` holds the agreement's hash H and its link: fetch the link, hash the bytes with SHA-256, and sign only if they match. Send the same request again with `PAYMENT-SIGNATURE`. The same answer carries MPP's challenge, `WWW-Authenticate: Payment … method=\"evm\", intent=\"charge\"`, for the same amount of the same token to the same payee, with an agreement of its own: its `opaque` (base64url JSON) holds `legalContext`, `lcp:sha256:` and that agreement's H, and `legalContextUrl`, its link. Check it the same way, and pay with `Authorization: Payment <credential>`, an `authorization` credential (EIP-3009) as `mppx` signs it. Pay one challenge, not both.","headers":{"PAYMENT-REQUIRED":{"schema":{"type":"string"}},"WWW-Authenticate":{"description":"MPP's `Payment` challenge, method `evm`, intent `charge`.","schema":{"type":"string"}}}},"502":{"description":"Paid, and not delivered: the seller tried again, and gave up. `PAYMENT-RESPONSE` holds the settlement, which succeeded; the body is the purchase."},"503":{"description":"Before a payment: the network named is not offered now, or the agreement could not be issued; nothing was taken. After a payment: paid, and not yet delivered, the seller tries again; `PAYMENT-RESPONSE` holds the settlement, which succeeded, `Retry-After` when to ask again, and the body is the purchase."}}}},"/test/buy/yield-curve-decade":{"post":{"operationId":"test_buy_yield_curve_decade","summary":"Test checkout for US Treasury yield curves, 2015 to 2024","description":"A checkout for testing an agent: its 402 advertises a hash with one character changed, so an agent that checks signs nothing. Nothing is sold here.","requestBody":{"required":false,"content":{"application/json":{"schema":{"type":"object","additionalProperties":false,"required":[],"properties":{"network":{"type":"string","enum":["eip155:84532","eip155:5042002","eip155:43113","hedera:testnet","stellar:testnet","solana:EtWTRABZaYq6iMfeYKouRu166VU2xqa1","xrpl:1","algorand:SGO1GKSzyE7IEPItTxCByw9x8FmnrCDe","eip155:11155111","eip155:421614","eip155:11155420","eip155:80002","eip155:1301","eip155:4801","eip155:763373","eip155:11142220","eip155:10143","eip155:1328","eip155:14601","eip155:2910","eip155:338","eip155:688689"],"description":"The network the checkout is paid on, a CAIP-2 id; without it, `eip155:84532`. The paid request repeats it, as it repeats the whole request."}}},"example":{}}}},"responses":{"402":{"description":"The test checkout's challenge, whose hash does not match its agreement."}}}},"/test/buy/yield-curve-2024":{"post":{"operationId":"test_buy_yield_curve_2024","summary":"Test checkout for US Treasury yield curves, 2024","description":"A checkout for testing an agent: its 402 advertises a hash with one character changed, so an agent that checks signs nothing. Nothing is sold here.","requestBody":{"required":false,"content":{"application/json":{"schema":{"type":"object","additionalProperties":false,"required":[],"properties":{"network":{"type":"string","enum":["eip155:84532","eip155:5042002","eip155:43113","hedera:testnet","stellar:testnet","solana:EtWTRABZaYq6iMfeYKouRu166VU2xqa1","xrpl:1","algorand:SGO1GKSzyE7IEPItTxCByw9x8FmnrCDe","eip155:11155111","eip155:421614","eip155:11155420","eip155:80002","eip155:1301","eip155:4801","eip155:763373","eip155:11142220","eip155:10143","eip155:1328","eip155:14601","eip155:2910","eip155:338","eip155:688689"],"description":"The network the checkout is paid on, a CAIP-2 id; without it, `eip155:84532`. The paid request repeats it, as it repeats the whole request."}}},"example":{}}}},"responses":{"402":{"description":"The test checkout's challenge, whose hash does not match its agreement."}}}},"/checkout-sessions":{"post":{"operationId":"ucp_create_checkout","summary":"Open a UCP checkout","description":"One line, one offer, quantity 1. At `ready_for_complete` the checkout's `ucp.payment_handlers[\"com.integraledger.lcp.x402\"]` declaration holds, as its `config`, the x402 `PaymentRequired` whose `extensions.legalContext` carries H, and its `links[]` the `legal_context` link titled `lcp:sha256:` and H. For demonstration only. This transaction runs on a test network with test money, and has no value.","externalDocs":{"url":"https://ucp.dev/2026-08-25/specification/shopping/checkout/rest"},"parameters":[{"$ref":"#/components/parameters/ucp_agent"},{"$ref":"#/components/parameters/idempotency_key"},{"$ref":"#/components/parameters/request_id"},{"$ref":"#/components/parameters/signature"},{"$ref":"#/components/parameters/signature_input"},{"$ref":"#/components/parameters/content_digest"}],"requestBody":{"required":true,"content":{"application/json":{"schema":{"$ref":"#/components/schemas/checkout"}}}},"responses":{"201":{"description":"The checkout, or UCP's error response.","content":{"application/json":{"schema":{"$ref":"#/components/schemas/checkout_response"}}}},"401":{"description":"The platform's signature is missing or does not verify against its profile's keys."},"409":{"description":"The idempotency key was used with another body."},"422":{"description":"The platform's profile is malformed, or its UCP version is not this shop's."},"424":{"description":"The platform's profile could not be fetched."}}}},"/checkout-sessions/{id}":{"parameters":[{"$ref":"#/components/parameters/checkout_id"}],"get":{"operationId":"ucp_get_checkout","summary":"Read a UCP checkout","description":"The checkout as it stands. For demonstration only. This transaction runs on a test network with test money, and has no value.","externalDocs":{"url":"https://ucp.dev/2026-08-25/specification/shopping/checkout/rest"},"parameters":[{"$ref":"#/components/parameters/ucp_agent"},{"$ref":"#/components/parameters/request_id"},{"$ref":"#/components/parameters/signature"},{"$ref":"#/components/parameters/signature_input"},{"$ref":"#/components/parameters/content_digest"}],"responses":{"200":{"description":"The checkout, or UCP's error response.","content":{"application/json":{"schema":{"$ref":"#/components/schemas/checkout_response"}}}},"401":{"description":"The platform's signature is missing or does not verify against its profile's keys."},"409":{"description":"The idempotency key was used with another body."},"422":{"description":"The platform's profile is malformed, or its UCP version is not this shop's."},"424":{"description":"The platform's profile could not be fetched."}}},"put":{"operationId":"ucp_update_checkout","summary":"Update a UCP checkout","description":"The whole checkout, as it is to be. Each change of its terms issues a new agreement, with its own H. At `ready_for_complete` the checkout's `ucp.payment_handlers[\"com.integraledger.lcp.x402\"]` declaration holds, as its `config`, the x402 `PaymentRequired` whose `extensions.legalContext` carries H, and its `links[]` the `legal_context` link titled `lcp:sha256:` and H. For demonstration only. This transaction runs on a test network with test money, and has no value.","externalDocs":{"url":"https://ucp.dev/2026-08-25/specification/shopping/checkout/rest"},"parameters":[{"$ref":"#/components/parameters/ucp_agent"},{"$ref":"#/components/parameters/idempotency_key"},{"$ref":"#/components/parameters/request_id"},{"$ref":"#/components/parameters/signature"},{"$ref":"#/components/parameters/signature_input"},{"$ref":"#/components/parameters/content_digest"}],"requestBody":{"required":true,"content":{"application/json":{"schema":{"$ref":"#/components/schemas/checkout"}}}},"responses":{"200":{"description":"The checkout, or UCP's error response.","content":{"application/json":{"schema":{"$ref":"#/components/schemas/checkout_response"}}}},"401":{"description":"The platform's signature is missing or does not verify against its profile's keys."},"409":{"description":"The idempotency key was used with another body."},"422":{"description":"The platform's profile is malformed, or its UCP version is not this shop's."},"424":{"description":"The platform's profile could not be fetched."}}}},"/checkout-sessions/{id}/complete":{"parameters":[{"$ref":"#/components/parameters/checkout_id"}],"post":{"operationId":"ucp_complete_checkout","summary":"Complete a UCP checkout","description":"Pay it: `payment.instruments` holds one instrument through the declaration of the network chosen (`handler_id` `lcp_x402_<network slug>`, as the checkout lists it; `type` `x402`), whose `credential` is `{type: \"x402\", x402Version: 2, paymentPayload, paymentRequirements}`: the x402 payment signed for the option in the handler's `config`. A failed payment is a business outcome, `payment_failed`, not an error status. For demonstration only. This transaction runs on a test network with test money, and has no value.","externalDocs":{"url":"https://ucp.dev/2026-08-25/specification/shopping/checkout/rest"},"parameters":[{"$ref":"#/components/parameters/ucp_agent"},{"$ref":"#/components/parameters/idempotency_key"},{"$ref":"#/components/parameters/request_id"},{"$ref":"#/components/parameters/signature"},{"$ref":"#/components/parameters/signature_input"},{"$ref":"#/components/parameters/content_digest"}],"requestBody":{"required":true,"content":{"application/json":{"schema":{"$ref":"#/components/schemas/checkout"}}}},"responses":{"200":{"description":"The checkout, or UCP's error response.","content":{"application/json":{"schema":{"$ref":"#/components/schemas/checkout_response"}}}},"401":{"description":"The platform's signature is missing or does not verify against its profile's keys."},"409":{"description":"The idempotency key was used with another body."},"422":{"description":"The platform's profile is malformed, or its UCP version is not this shop's."},"424":{"description":"The platform's profile could not be fetched."}}}},"/checkout-sessions/{id}/cancel":{"parameters":[{"$ref":"#/components/parameters/checkout_id"}],"post":{"operationId":"ucp_cancel_checkout","summary":"Cancel a UCP checkout","description":"Cancel it before it is paid. For demonstration only. This transaction runs on a test network with test money, and has no value.","externalDocs":{"url":"https://ucp.dev/2026-08-25/specification/shopping/checkout/rest"},"parameters":[{"$ref":"#/components/parameters/ucp_agent"},{"$ref":"#/components/parameters/idempotency_key"},{"$ref":"#/components/parameters/request_id"},{"$ref":"#/components/parameters/signature"},{"$ref":"#/components/parameters/signature_input"},{"$ref":"#/components/parameters/content_digest"}],"responses":{"200":{"description":"The checkout, or UCP's error response.","content":{"application/json":{"schema":{"$ref":"#/components/schemas/checkout_response"}}}},"401":{"description":"The platform's signature is missing or does not verify against its profile's keys."},"409":{"description":"The idempotency key was used with another body."},"422":{"description":"The platform's profile is malformed, or its UCP version is not this shop's."},"424":{"description":"The platform's profile could not be fetched."}}}},"/orders/{id}":{"parameters":[{"$ref":"#/components/parameters/order_id"}],"get":{"operationId":"ucp_get_order","summary":"Read a UCP order","description":"The order, to the platform whose checkout made it, when the request is signed with that platform's key. Anyone else is answered the kit's summary of the delivery: its state, size and hash, never what was bought. For demonstration only. This transaction runs on a test network with test money, and has no value.","externalDocs":{"url":"https://ucp.dev/2026-08-25/specification/shopping/order/rest"},"parameters":[{"$ref":"#/components/parameters/ucp_agent"},{"$ref":"#/components/parameters/request_id"},{"$ref":"#/components/parameters/signature"},{"$ref":"#/components/parameters/signature_input"},{"$ref":"#/components/parameters/content_digest"}],"responses":{"200":{"description":"The order, or UCP's error response.","content":{"application/json":{"schema":{"$ref":"#/components/schemas/order_response"}}}},"401":{"description":"The platform's signature is missing or does not verify against its profile's keys."},"409":{"description":"The idempotency key was used with another body."},"422":{"description":"The platform's profile is malformed, or its UCP version is not this shop's."},"424":{"description":"The platform's profile could not be fetched."}}}}},"components":{"parameters":{"ucp_agent":{"name":"UCP-Agent","in":"header","required":true,"description":"Your platform's profile: `profile=\"<the URL of your /.well-known/ucp>\"` (RFC 8941 dictionary). This shop fetches it, and reads its capabilities and its order capability's `webhook_url`.","schema":{"type":"string"}},"idempotency_key":{"name":"Idempotency-Key","in":"header","required":true,"description":"A UUID. The same key with the same body answers what it answered; with another body, `409`. Kept for 24 hours.","schema":{"type":"string","format":"uuid"}},"request_id":{"name":"Request-Id","in":"header","required":false,"description":"A UUID, for tracing.","schema":{"type":"string","format":"uuid"}},"signature":{"name":"Signature","in":"header","required":false,"description":"RFC 9421 HTTP Message Signature by a key in your profile's `keys[]`.","schema":{"type":"string"}},"signature_input":{"name":"Signature-Input","in":"header","required":false,"schema":{"type":"string"}},"content_digest":{"name":"Content-Digest","in":"header","required":false,"schema":{"type":"string"}},"checkout_id":{"name":"id","in":"path","required":true,"description":"The checkout session's id.","schema":{"type":"string"}},"order_id":{"name":"id","in":"path","required":true,"description":"The order's id.","schema":{"type":"string"}}},"schemas":{"checkout":{"$ref":"https://ucp.dev/2026-08-25/schemas/shopping/checkout.json"},"order":{"$ref":"https://ucp.dev/2026-08-25/schemas/shopping/order.json"},"error_response":{"$ref":"https://ucp.dev/2026-08-25/schemas/common/types/error_response.json"},"checkout_response":{"oneOf":[{"$ref":"#/components/schemas/checkout"},{"$ref":"#/components/schemas/error_response"}]},"order_response":{"oneOf":[{"$ref":"#/components/schemas/order"},{"$ref":"#/components/schemas/error_response"}]}}}}